31355117 has 4 divisors (see below), whose sum is σ = 31368156. Its totient is φ = 31342080.

The previous prime is 31355099. The next prime is 31355131. The reversal of 31355117 is 71155313.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 6295081 + 25060036 = 2509^2 + 5006^2 .

It is a cyclic number.

It is not a de Polignac number, because 31355117 - 2²⁰ = 30306541 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 (31355197) 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, 1748 + ... + 8109.

It is an arithmetic number, because the mean of its divisors is an integer number (7842039).

Almost surely, 2^31355117 is an apocalyptic number.

It is an amenable number.

31355117 is a deficient number, since it is larger than the sum of its proper divisors (13039).

31355117 is an equidigital number, since it uses as much as digits as its factorization.

31355117 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13038.

The product of its digits is 1575, while the sum is 26.

The square root of 31355117 is about 5599.5640008844. The cubic root of 31355117 is about 315.3330382091. Note that the first 3 decimals are identical.

The spelling of 31355117 in words is "thirty-one million, three hundred fifty-five thousand, one hundred seventeen".