31391413 has 4 divisors (see below), whose sum is σ = 31696288. Its totient is φ = 31086540.

The previous prime is 31391383. The next prime is 31391447. The reversal of 31391413 is 31419313.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 31419313 = 661 ⋅47533.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-31391413 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31391713) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 152283 + ... + 152488.

It is an arithmetic number, because the mean of its divisors is an integer number (7924072).

Almost surely, 2^31391413 is an apocalyptic number.

It is an amenable number.

31391413 is a deficient number, since it is larger than the sum of its proper divisors (304875).

31391413 is a wasteful number, since it uses less digits than its factorization.

31391413 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 304874.

The product of its digits is 972, while the sum is 25.

The square root of 31391413 is about 5602.8040301263. The cubic root of 31391413 is about 315.4546655074.

The spelling of 31391413 in words is "thirty-one million, three hundred ninety-one thousand, four hundred thirteen".