139238631 has 48 divisors (see below), whose sum is σ = 244857600. Its totient is φ = 74473344.

The previous prime is 139238629. The next prime is 139238633. The reversal of 139238631 is 136832931.

139238631 is a `hidden beast` number, since 13 + 9 + 2 + 3 + 8 + 631 = 666.

139238631 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (139238629) and next prime (139238633).

It is not a de Polignac number, because 139238631 - 2¹ = 139238629 is a prime.

It is a super-2 number, since 2×139238631² = 38774792725508322, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (139238633) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 105880 + ... + 107186.

It is an arithmetic number, because the mean of its divisors is an integer number (5101200).

Almost surely, 2^139238631 is an apocalyptic number.

139238631 is a deficient number, since it is larger than the sum of its proper divisors (105618969).

139238631 is a wasteful number, since it uses less digits than its factorization.

139238631 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1428 (or 1425 counting only the distinct ones).

The product of its digits is 23328, while the sum is 36.

The square root of 139238631 is about 11799.9419913828. The cubic root of 139238631 is about 518.3064119855.

The spelling of 139238631 in words is "one hundred thirty-nine million, two hundred thirty-eight thousand, six hundred thirty-one".