161731054520 has 64 divisors (see below), whose sum is σ = 415933859520. Its totient is φ = 55443446784.

The previous prime is 161731054519. The next prime is 161731054553. The reversal of 161731054520 is 25450137161.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (35).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2406494 + ... + 2472786.

It is an arithmetic number, because the mean of its divisors is an integer number (6498966555).

Almost surely, 2^161731054520 is an apocalyptic number.

161731054520 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

161731054520 is an abundant number, since it is smaller than the sum of its proper divisors (254202805000).

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

161731054520 is a wasteful number, since it uses less digits than its factorization.

161731054520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 75024 (or 75020 counting only the distinct ones).

The product of its (nonzero) digits is 25200, while the sum is 35.

The spelling of 161731054520 in words is "one hundred sixty-one billion, seven hundred thirty-one million, fifty-four thousand, five hundred twenty".