315210421 has 2 divisors, whose sum is σ = 315210422. Its totient is φ = 315210420.

The previous prime is 315210397. The next prime is 315210473. The reversal of 315210421 is 124012513.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 166126321 + 149084100 = 12889^2 + 12210^2 .

It is a cyclic number.

It is not a de Polignac number, because 315210421 - 2²⁵ = 281655989 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (315210491) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 157605210 + 157605211.

It is an arithmetic number, because the mean of its divisors is an integer number (157605211).

Almost surely, 2^315210421 is an apocalyptic number.

It is an amenable number.

315210421 is a deficient number, since it is larger than the sum of its proper divisors (1).

315210421 is an equidigital number, since it uses as much as digits as its factorization.

315210421 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 240, while the sum is 19.

The square root of 315210421 is about 17754.1662997731. The cubic root of 315210421 is about 680.5606830437.

Adding to 315210421 its reverse (124012513), we get a palindrome (439222934).

The spelling of 315210421 in words is "three hundred fifteen million, two hundred ten thousand, four hundred twenty-one".