161893431 has 32 divisors (see below), whose sum is σ = 290234880. Its totient is φ = 87067008.

The previous prime is 161893411. The next prime is 161893447. The reversal of 161893431 is 134398161.

161893431 is a `hidden beast` number, since 1 + 618 + 9 + 3 + 4 + 31 = 666.

161893431 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 161893431 - 2⁶ = 161893367 is a prime.

It is a super-2 number, since 2×161893431² = 52418966001903522, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161893411) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 21981 + ... + 28406.

It is an arithmetic number, because the mean of its divisors is an integer number (9069840).

Almost surely, 2^161893431 is an apocalyptic number.

161893431 is a deficient number, since it is larger than the sum of its proper divisors (128341449).

161893431 is a wasteful number, since it uses less digits than its factorization.

161893431 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 50420 (or 50414 counting only the distinct ones).

The product of its digits is 15552, while the sum is 36.

The square root of 161893431 is about 12723.7349469407. The cubic root of 161893431 is about 545.0166153787.

The spelling of 161893431 in words is "one hundred sixty-one million, eight hundred ninety-three thousand, four hundred thirty-one".