161001123840 has 624 divisors, whose sum is σ = 606799764480. Its totient is φ = 39335362560.

The previous prime is 161001123817. The next prime is 161001123863. The reversal of 161001123840 is 48321100161.

It is a happy number.

161001123840 is a `hidden beast` number, since 1 + 610 + 0 + 1 + 1 + 2 + 3 + 8 + 40 = 666.

It is an interprime number because it is at equal distance from previous prime (161001123817) and next prime (161001123863).

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 108563739 + ... + 108565221.

It is an arithmetic number, because the mean of its divisors is an integer number (972435520).

Almost surely, 2^161001123840 is an apocalyptic number.

161001123840 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 161001123840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (303399882240).

161001123840 is an abundant number, since it is smaller than the sum of its proper divisors (445798640640).

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

161001123840 is a wasteful number, since it uses less digits than its factorization.

161001123840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1568 (or 1543 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 27.

The spelling of 161001123840 in words is "one hundred sixty-one billion, one million, one hundred twenty-three thousand, eight hundred forty".