31292161 has 4 divisors (see below), whose sum is σ = 31361092. Its totient is φ = 31223232.

The previous prime is 31292111. The next prime is 31292171. The reversal of 31292161 is 16129213.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 14938225 + 16353936 = 3865^2 + 4044^2 .

It is a cyclic number.

It is not a de Polignac number, because 31292161 - 2⁹ = 31291649 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (31292111) 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, 33780 + ... + 34693.

It is an arithmetic number, because the mean of its divisors is an integer number (7840273).

Almost surely, 2^31292161 is an apocalyptic number.

It is an amenable number.

31292161 is a deficient number, since it is larger than the sum of its proper divisors (68931).

31292161 is an equidigital number, since it uses as much as digits as its factorization.

31292161 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 68930.

The product of its digits is 648, while the sum is 25.

The square root of 31292161 is about 5593.9396671755. The cubic root of 31292161 is about 315.1218509017.

The spelling of 31292161 in words is "thirty-one million, two hundred ninety-two thousand, one hundred sixty-one".