394977217 has 2 divisors, whose sum is σ = 394977218. Its totient is φ = 394977216.

The previous prime is 394977203. The next prime is 394977223. The reversal of 394977217 is 712779493.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 323676081 + 71301136 = 17991^2 + 8444^2 .

It is a cyclic number.

It is not a de Polignac number, because 394977217 - 2¹⁵ = 394944449 is a prime.

It is not a weakly prime, because it can be changed into another prime (394977277) 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, 197488608 + 197488609.

It is an arithmetic number, because the mean of its divisors is an integer number (197488609).

Almost surely, 2^394977217 is an apocalyptic number.

It is an amenable number.

394977217 is a deficient number, since it is larger than the sum of its proper divisors (1).

394977217 is an equidigital number, since it uses as much as digits as its factorization.

394977217 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 666792, while the sum is 49.

The square root of 394977217 is about 19874.0337375179. The cubic root of 394977217 is about 733.7092851695.

The spelling of 394977217 in words is "three hundred ninety-four million, nine hundred seventy-seven thousand, two hundred seventeen".