139437931 has 2 divisors, whose sum is σ = 139437932. Its totient is φ = 139437930.

The previous prime is 139437929. The next prime is 139437953. The reversal of 139437931 is 139734931.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 139437931 - 2¹ = 139437929 is a prime.

It is a super-2 number, since 2×139437931² = 38885873203121522, which contains 22 as substring.

Together with 139437929, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (139437911) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 69718965 + 69718966.

It is an arithmetic number, because the mean of its divisors is an integer number (69718966).

Almost surely, 2^139437931 is an apocalyptic number.

139437931 is a deficient number, since it is larger than the sum of its proper divisors (1).

139437931 is an equidigital number, since it uses as much as digits as its factorization.

139437931 is an evil number, because the sum of its binary digits is even.

The product of its digits is 61236, while the sum is 40.

The square root of 139437931 is about 11808.3839283790. The cubic root of 139437931 is about 518.5535876932.

The spelling of 139437931 in words is "one hundred thirty-nine million, four hundred thirty-seven thousand, nine hundred thirty-one".