8161990172 has 18 divisors (see below), whose sum is σ = 16615480392. Its totient is φ = 3497995704.

The previous prime is 8161990157. The next prime is 8161990211. The reversal of 8161990172 is 2710991618.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 20821208 + ... + 20821599.

It is an arithmetic number, because the mean of its divisors is an integer number (923082244).

Almost surely, 2^8161990172 is an apocalyptic number.

It is an amenable number.

8161990172 is an abundant number, since it is smaller than the sum of its proper divisors (8453490220).

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

8161990172 is a wasteful number, since it uses less digits than its factorization.

8161990172 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 41642825 (or 41642816 counting only the distinct ones).

The product of its (nonzero) digits is 54432, while the sum is 44.

The square root of 8161990172 is about 90343.7334406764. The cubic root of 8161990172 is about 2013.4090783919.

The spelling of 8161990172 in words is "eight billion, one hundred sixty-one million, nine hundred ninety thousand, one hundred seventy-two".