31168913 has 4 divisors (see below), whose sum is σ = 31490340. Its totient is φ = 30847488.

The previous prime is 31168909. The next prime is 31168927. The reversal of 31168913 is 31986113.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 31986113 = 347 ⋅92179.

It can be written as a sum of positive squares in 2 ways, for example, as 18939904 + 12229009 = 4352^2 + 3497^2 .

It is a cyclic number.

It is not a de Polignac number, because 31168913 - 2² = 31168909 is a prime.

It is a super-2 number, since 2×31168913² = 1943002275203138, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 31168913.

It is not an unprimeable number, because it can be changed into a prime (31168513) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 160568 + ... + 160761.

It is an arithmetic number, because the mean of its divisors is an integer number (7872585).

Almost surely, 2^31168913 is an apocalyptic number.

It is an amenable number.

31168913 is a deficient number, since it is larger than the sum of its proper divisors (321427).

31168913 is an equidigital number, since it uses as much as digits as its factorization.

31168913 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 321426.

The product of its digits is 3888, while the sum is 32.

The square root of 31168913 is about 5582.9125911123. The cubic root of 31168913 is about 314.7075912481.

The spelling of 31168913 in words is "thirty-one million, one hundred sixty-eight thousand, nine hundred thirteen".