312639521 has 2 divisors, whose sum is σ = 312639522. Its totient is φ = 312639520.

The previous prime is 312639511. The next prime is 312639559. The reversal of 312639521 is 125936213.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 312582400 + 57121 = 17680^2 + 239^2 .

It is a cyclic number.

It is not a de Polignac number, because 312639521 - 2¹⁰ = 312638497 is a prime.

It is a super-2 number, since 2×312639521² = 195486940182218882, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (312639511) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 156319760 + 156319761.

It is an arithmetic number, because the mean of its divisors is an integer number (156319761).

Almost surely, 2^312639521 is an apocalyptic number.

It is an amenable number.

312639521 is a deficient number, since it is larger than the sum of its proper divisors (1).

312639521 is an equidigital number, since it uses as much as digits as its factorization.

312639521 is an evil number, because the sum of its binary digits is even.

The product of its digits is 9720, while the sum is 32.

The square root of 312639521 is about 17681.6153391029. The cubic root of 312639521 is about 678.7053806587.

The spelling of 312639521 in words is "three hundred twelve million, six hundred thirty-nine thousand, five hundred twenty-one".