161061949440 has 936 divisors, whose sum is σ = 688284815400. Its totient is φ = 34615590912.

The previous prime is 161061949427. The next prime is 161061949453. The reversal of 161061949440 is 44949160161.

161061949440 is a `hidden beast` number, since 1 + 6 + 10 + 6 + 194 + 9 + 440 = 666.

It is an interprime number because it is at equal distance from previous prime (161061949427) and next prime (161061949453).

It can be written as a sum of positive squares in 4 ways, for example, as 67983261696 + 93078687744 = 260736^2 + 305088^2 .

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 153538036 + ... + 153539084.

It is an arithmetic number, because the mean of its divisors is an integer number (735347025).

Almost surely, 2^161061949440 is an apocalyptic number.

161061949440 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 161061949440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (344142407700).

161061949440 is an abundant number, since it is smaller than the sum of its proper divisors (527222865960).

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

161061949440 is a wasteful number, since it uses less digits than its factorization.

161061949440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1115 (or 1083 counting only the distinct ones).

The product of its (nonzero) digits is 186624, while the sum is 45.

The spelling of 161061949440 in words is "one hundred sixty-one billion, sixty-one million, nine hundred forty-nine thousand, four hundred forty".