161594431 has 4 divisors (see below), whose sum is σ = 161620864. Its totient is φ = 161568000.

The previous prime is 161594423. The next prime is 161594441. The reversal of 161594431 is 134495161.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 161594431 - 2³ = 161594423 is a prime.

It is a super-2 number, since 2×161594431² = 52225520260427522, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161594441) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1186 + ... + 18016.

It is an arithmetic number, because the mean of its divisors is an integer number (40405216).

Almost surely, 2^161594431 is an apocalyptic number.

161594431 is a deficient number, since it is larger than the sum of its proper divisors (26433).

161594431 is an equidigital number, since it uses as much as digits as its factorization.

161594431 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26432.

The product of its digits is 12960, while the sum is 34.

The square root of 161594431 is about 12711.9798221992. The cubic root of 161594431 is about 544.6808793057.

The spelling of 161594431 in words is "one hundred sixty-one million, five hundred ninety-four thousand, four hundred thirty-one".