161185040640 has 1152 divisors, whose sum is σ = 648763637760. Its totient is φ = 37623398400.

The previous prime is 161185040633. The next prime is 161185040647. The reversal of 161185040640 is 46040581161.

161185040640 is a `hidden beast` number, since 1 + 6 + 1 + 1 + 8 + 5 + 0 + 4 + 0 + 640 = 666.

It is an interprime number because it is at equal distance from previous prime (161185040633) and next prime (161185040647).

It is a tau number, because it is divible by the number of its divisors (1152).

It is a super-2 number, since 2×161185040640² (a number of 23 digits) contains 22 as substring.

It is a hoax number, since the sum of its digits (36) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 161185040595 and 161185040604.

It is not an unprimeable number, because it can be changed into a prime (161185040647) by changing a digit.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 988865199 + ... + 988865361.

It is an arithmetic number, because the mean of its divisors is an integer number (563162880).

Almost surely, 2^161185040640 is an apocalyptic number.

161185040640 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 161185040640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (324381818880).

161185040640 is an abundant number, since it is smaller than the sum of its proper divisors (487578597120).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

161185040640 is a wasteful number, since it uses less digits than its factorization.

161185040640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 308 (or 288 counting only the distinct ones).

The product of its (nonzero) digits is 23040, while the sum is 36.

The spelling of 161185040640 in words is "one hundred sixty-one billion, one hundred eighty-five million, forty thousand, six hundred forty".