921317251 has 2 divisors, whose sum is σ = 921317252. Its totient is φ = 921317250.

The previous prime is 921317219. The next prime is 921317281. The reversal of 921317251 is 152713129.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 921317251 - 2⁵ = 921317219 is a prime.

It is not a weakly prime, because it can be changed into another prime (921317281) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 460658625 + 460658626.

It is an arithmetic number, because the mean of its divisors is an integer number (460658626).

Almost surely, 2^921317251 is an apocalyptic number.

921317251 is a deficient number, since it is larger than the sum of its proper divisors (1).

921317251 is an equidigital number, since it uses as much as digits as its factorization.

921317251 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3780, while the sum is 31.

The square root of 921317251 is about 30353.2082488820. The cubic root of 921317251 is about 973.0527873221.

The spelling of 921317251 in words is "nine hundred twenty-one million, three hundred seventeen thousand, two hundred fifty-one".