161581057788 has 12 divisors (see below), whose sum is σ = 377022468200. Its totient is φ = 53860352592.

The previous prime is 161581057787. The next prime is 161581057789. The reversal of 161581057788 is 887750185161.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (161581057787) and next prime (161581057789).

It is a tau number, because it is divible by the number of its divisors (12).

It is a super-2 number, since 2×161581057788² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161581057783) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6732544063 + ... + 6732544086.

Almost surely, 2^161581057788 is an apocalyptic number.

It is an amenable number.

161581057788 is an abundant number, since it is smaller than the sum of its proper divisors (215441410412).

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

161581057788 is a wasteful number, since it uses less digits than its factorization.

161581057788 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13465088156 (or 13465088154 counting only the distinct ones).

The product of its (nonzero) digits is 3763200, while the sum is 57.

The spelling of 161581057788 in words is "one hundred sixty-one billion, five hundred eighty-one million, fifty-seven thousand, seven hundred eighty-eight".