31138379 has 4 divisors (see below), whose sum is σ = 31329576. Its totient is φ = 30947184.

The previous prime is 31138313. The next prime is 31138381. The reversal of 31138379 is 97383113.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 97383113 = 19 ⋅5125427.

It is a cyclic number.

It is not a de Polignac number, because 31138379 - 2¹² = 31134283 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (31138309) 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 3 ways as a sum of consecutive naturals, for example, 95354 + ... + 95679.

It is an arithmetic number, because the mean of its divisors is an integer number (7832394).

Almost surely, 2^31138379 is an apocalyptic number.

31138379 is a deficient number, since it is larger than the sum of its proper divisors (191197).

31138379 is a wasteful number, since it uses less digits than its factorization.

31138379 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 191196.

The product of its digits is 13608, while the sum is 35.

The square root of 31138379 is about 5580.1773269315. The cubic root of 31138379 is about 314.6047920141.

The spelling of 31138379 in words is "thirty-one million, one hundred thirty-eight thousand, three hundred seventy-nine".