315221631 has 4 divisors (see below), whose sum is σ = 420295512. Its totient is φ = 210147752.

The previous prime is 315221629. The next prime is 315221651. The reversal of 315221631 is 136122513.

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

It is a cyclic number.

It is not a de Polignac number, because 315221631 - 2¹ = 315221629 is a prime.

It is a super-2 number, since 2×315221631² = 198729353300600322, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (315221651) 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, 52536936 + ... + 52536941.

It is an arithmetic number, because the mean of its divisors is an integer number (105073878).

Almost surely, 2^315221631 is an apocalyptic number.

315221631 is a deficient number, since it is larger than the sum of its proper divisors (105073881).

315221631 is a wasteful number, since it uses less digits than its factorization.

315221631 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 105073880.

The product of its digits is 1080, while the sum is 24.

The square root of 315221631 is about 17754.4819975126. The cubic root of 315221631 is about 680.5687506649.

It can be divided in two parts, 31522 and 1631, that added together give a triangular number (33153 = T₂₅₇).

The spelling of 315221631 in words is "three hundred fifteen million, two hundred twenty-one thousand, six hundred thirty-one".