315408221 has 4 divisors (see below), whose sum is σ = 315487200. Its totient is φ = 315329244.

The previous prime is 315408209. The next prime is 315408251. The reversal of 315408221 is 122804513.

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: 122804513 = 13 ⋅9446501.

It is a cyclic number.

It is not a de Polignac number, because 315408221 - 2²⁶ = 248299357 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 (315408251) 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, 33161 + ... + 41598.

It is an arithmetic number, because the mean of its divisors is an integer number (78871800).

Almost surely, 2^315408221 is an apocalyptic number.

It is an amenable number.

315408221 is a deficient number, since it is larger than the sum of its proper divisors (78979).

315408221 is an equidigital number, since it uses as much as digits as its factorization.

315408221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 78978.

The product of its (nonzero) digits is 1920, while the sum is 26.

The square root of 315408221 is about 17759.7359496137. The cubic root of 315408221 is about 680.7030078170.

The spelling of 315408221 in words is "three hundred fifteen million, four hundred eight thousand, two hundred twenty-one".