31087139 has 2 divisors, whose sum is σ = 31087140. Its totient is φ = 31087138.

The previous prime is 31087117. The next prime is 31087153. The reversal of 31087139 is 93178013.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 31087139 - 2²⁴ = 14309923 is a prime.

It is a super-2 number, since 2×31087139² = 1932820422410642, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (31087039) 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 as a sum of consecutive naturals, namely, 15543569 + 15543570.

It is an arithmetic number, because the mean of its divisors is an integer number (15543570).

Almost surely, 2^31087139 is an apocalyptic number.

31087139 is a deficient number, since it is larger than the sum of its proper divisors (1).

31087139 is an equidigital number, since it uses as much as digits as its factorization.

31087139 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 4536, while the sum is 32.

The square root of 31087139 is about 5575.5841846393. The cubic root of 31087139 is about 314.4321304897.

The spelling of 31087139 in words is "thirty-one million, eighty-seven thousand, one hundred thirty-nine".