155861431 has 8 divisors (see below), whose sum is σ = 171437328. Its totient is φ = 141691000.

The previous prime is 155861413. The next prime is 155861437. The reversal of 155861431 is 134168551.

It is not a de Polignac number, because 155861431 - 2⁹ = 155860919 is a prime.

It is a super-2 number, since 2×155861431² = 48585571346735522, 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 (155861437) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 57220 + ... + 59881.

It is an arithmetic number, because the mean of its divisors is an integer number (21429666).

Almost surely, 2^155861431 is an apocalyptic number.

155861431 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

155861431 is a deficient number, since it is larger than the sum of its proper divisors (15575897).

155861431 is an equidigital number, since it uses as much as digits as its factorization.

155861431 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 117134 (or 117112 counting only the distinct ones).

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

The square root of 155861431 is about 12484.4475648705. The cubic root of 155861431 is about 538.1618237380.

The spelling of 155861431 in words is "one hundred fifty-five million, eight hundred sixty-one thousand, four hundred thirty-one".