161942581867880 has 64 divisors (see below), whose sum is σ = 418416240254400. Its totient is φ = 55788832028160.

The previous prime is 161942581867837. The next prime is 161942581867883. The reversal of 161942581867880 is 88768185249161.

It is a super-2 number, since 2×161942581867880² (a number of 29 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 161942581867798 and 161942581867807.

It is not an unprimeable number, because it can be changed into a prime (161942581867883) 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, 9685552757 + ... + 9685569476.

It is an arithmetic number, because the mean of its divisors is an integer number (6537753753975).

Almost surely, 2^{161942581867880} is an apocalyptic number.

161942581867880 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

161942581867880 is an abundant number, since it is smaller than the sum of its proper divisors (256473658386520).

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

161942581867880 is a wasteful number, since it uses less digits than its factorization.

161942581867880 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19371122274 (or 19371122270 counting only the distinct ones).

The product of its (nonzero) digits is 371589120, while the sum is 74.

The spelling of 161942581867880 in words is "one hundred sixty-one trillion, nine hundred forty-two billion, five hundred eighty-one million, eight hundred sixty-seven thousand, eight hundred eighty".