161691925420 has 12 divisors (see below), whose sum is σ = 339553043424. Its totient is φ = 64676770160.

The previous prime is 161691925397. The next prime is 161691925463. The reversal of 161691925420 is 24529196161.

It is a super-2 number, since 2×161691925420² (a number of 23 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4042298116 + ... + 4042298155.

It is an arithmetic number, because the mean of its divisors is an integer number (28296086952).

Almost surely, 2^161691925420 is an apocalyptic number.

161691925420 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

161691925420 is an abundant number, since it is smaller than the sum of its proper divisors (177861118004).

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

161691925420 is a wasteful number, since it uses less digits than its factorization.

161691925420 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8084596280 (or 8084596278 counting only the distinct ones).

The product of its (nonzero) digits is 233280, while the sum is 46.

The spelling of 161691925420 in words is "one hundred sixty-one billion, six hundred ninety-one million, nine hundred twenty-five thousand, four hundred twenty".