31138605 has 48 divisors (see below), whose sum is σ = 56609280. Its totient is φ = 15813504.

The previous prime is 31138559. The next prime is 31138637. The reversal of 31138605 is 50683113.

It is not a de Polignac number, because 31138605 - 2¹¹ = 31136557 is a prime.

It is a super-2 number, since 2×31138605² = 1939225442692050, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 139524 + ... + 139746.

It is an arithmetic number, because the mean of its divisors is an integer number (1179360).

Almost surely, 2^31138605 is an apocalyptic number.

It is an amenable number.

31138605 is a deficient number, since it is larger than the sum of its proper divisors (25470675).

31138605 is a wasteful number, since it uses less digits than its factorization.

31138605 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 370 (or 367 counting only the distinct ones).

The product of its (nonzero) digits is 2160, while the sum is 27.

The square root of 31138605 is about 5580.1975771472. The cubic root of 31138605 is about 314.6055531382.

The spelling of 31138605 in words is "thirty-one million, one hundred thirty-eight thousand, six hundred five".