161661612402 has 32 divisors (see below), whose sum is σ = 359328067200. Its totient is φ = 53875198224.

The previous prime is 161661612389. The next prime is 161661612407. The reversal of 161661612402 is 204216166161.

161661612402 is a `hidden beast` number, since 1 + 6 + 16 + 616 + 1 + 24 + 0 + 2 = 666.

It is a super-2 number, since 2×161661612402² (a number of 23 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (161661612407) 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, 87213 + ... + 575264.

It is an arithmetic number, because the mean of its divisors is an integer number (11229002100).

Almost surely, 2^161661612402 is an apocalyptic number.

161661612402 is an abundant number, since it is smaller than the sum of its proper divisors (197666454798).

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

161661612402 is a wasteful number, since it uses less digits than its factorization.

161661612402 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 667007 (or 667001 counting only the distinct ones).

The product of its (nonzero) digits is 20736, while the sum is 36.

Adding to 161661612402 its reverse (204216166161), we get a palindrome (365877778563).

The spelling of 161661612402 in words is "one hundred sixty-one billion, six hundred sixty-one million, six hundred twelve thousand, four hundred two".