315620321 has 2 divisors, whose sum is σ = 315620322. Its totient is φ = 315620320.

The previous prime is 315620309. The next prime is 315620359. The reversal of 315620321 is 123026513.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 192654400 + 122965921 = 13880^2 + 11089^2 .

It is an emirp because it is prime and its reverse (123026513) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-315620321 is a prime.

It is not a weakly prime, because it can be changed into another prime (315620621) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 157810160 + 157810161.

It is an arithmetic number, because the mean of its divisors is an integer number (157810161).

Almost surely, 2^315620321 is an apocalyptic number.

It is an amenable number.

315620321 is a deficient number, since it is larger than the sum of its proper divisors (1).

315620321 is an equidigital number, since it uses as much as digits as its factorization.

315620321 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1080, while the sum is 23.

The square root of 315620321 is about 17765.7063186353. The cubic root of 315620321 is about 680.8555558989.

Adding to 315620321 its reverse (123026513), we get a palindrome (438646834).

The spelling of 315620321 in words is "three hundred fifteen million, six hundred twenty thousand, three hundred twenty-one".