161992138 has 72 divisors (see below), whose sum is σ = 327499200. Its totient is φ = 59708880.

The previous prime is 161992121. The next prime is 161992141. The reversal of 161992138 is 831299161.

It is a super-2 number, since 2×161992138² = 52482905547622088, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 161992138.

It is an unprimeable number.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 224943 + ... + 225661.

It is an arithmetic number, because the mean of its divisors is an integer number (4548600).

Almost surely, 2^161992138 is an apocalyptic number.

161992138 is an abundant number, since it is smaller than the sum of its proper divisors (165507062).

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

161992138 is a wasteful number, since it uses less digits than its factorization.

161992138 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 776 (or 758 counting only the distinct ones).

The product of its digits is 23328, while the sum is 40.

The square root of 161992138 is about 12727.6132090821. The cubic root of 161992138 is about 545.1273590637.

It can be divided in two parts, 161 and 992138, that added together give a palindrome (992299).

The spelling of 161992138 in words is "one hundred sixty-one million, nine hundred ninety-two thousand, one hundred thirty-eight".