161621025880 has 64 divisors (see below), whose sum is σ = 375502049280. Its totient is φ = 62542281600.

The previous prime is 161621025823. The next prime is 161621025883. The reversal of 161621025880 is 88520126161.

It is a happy number.

It is a super-2 number, since 2×161621025880² (a number of 23 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (40).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161621025883) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4036117 + ... + 4075963.

It is an arithmetic number, because the mean of its divisors is an integer number (5867219520).

Almost surely, 2^161621025880 is an apocalyptic number.

161621025880 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

161621025880 is an abundant number, since it is smaller than the sum of its proper divisors (213881023400).

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

161621025880 is a wasteful number, since it uses less digits than its factorization.

161621025880 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 43160 (or 43156 counting only the distinct ones).

The product of its (nonzero) digits is 46080, while the sum is 40.

The spelling of 161621025880 in words is "one hundred sixty-one billion, six hundred twenty-one million, twenty-five thousand, eight hundred eighty".