161558431 has 2 divisors, whose sum is σ = 161558432. Its totient is φ = 161558430.

The previous prime is 161558413. The next prime is 161558437. The reversal of 161558431 is 134855161.

Together with previous prime (161558413) it forms an Ormiston pair, because they use the same digits, order apart.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 161558431 - 2⁷ = 161558303 is a prime.

It is a super-2 number, since 2×161558431² = 52202253254363522, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (161558437) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 80779215 + 80779216.

It is an arithmetic number, because the mean of its divisors is an integer number (80779216).

Almost surely, 2^161558431 is an apocalyptic number.

161558431 is a deficient number, since it is larger than the sum of its proper divisors (1).

161558431 is an equidigital number, since it uses as much as digits as its factorization.

161558431 is an evil number, because the sum of its binary digits is even.

The product of its digits is 14400, while the sum is 34.

The square root of 161558431 is about 12710.5637561833. The cubic root of 161558431 is about 544.6404283078.

The spelling of 161558431 in words is "one hundred sixty-one million, five hundred fifty-eight thousand, four hundred thirty-one".