312187921 has 2 divisors, whose sum is σ = 312187922. Its totient is φ = 312187920.

The previous prime is 312187913. The next prime is 312187927. The reversal of 312187921 is 129781213.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 187553025 + 124634896 = 13695^2 + 11164^2 .

It is a cyclic number.

It is not a de Polignac number, because 312187921 - 2³ = 312187913 is a prime.

It is a super-2 number, since 2×312187921² = 194922596036604482, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (312187927) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 156093960 + 156093961.

It is an arithmetic number, because the mean of its divisors is an integer number (156093961).

Almost surely, 2^312187921 is an apocalyptic number.

It is an amenable number.

312187921 is a deficient number, since it is larger than the sum of its proper divisors (1).

312187921 is an equidigital number, since it uses as much as digits as its factorization.

312187921 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 6048, while the sum is 34.

The square root of 312187921 is about 17668.8403977171. The cubic root of 312187921 is about 678.3784321801.

The spelling of 312187921 in words is "three hundred twelve million, one hundred eighty-seven thousand, nine hundred twenty-one".