390945866 has 4 divisors (see below), whose sum is σ = 586418802. Its totient is φ = 195472932.

The previous prime is 390945847. The next prime is 390945869. The reversal of 390945866 is 668549093.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 345774025 + 45171841 = 18595^2 + 6721^2 .

It is not an unprimeable number, because it can be changed into a prime (390945869) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 97736465 + ... + 97736468.

Almost surely, 2^390945866 is an apocalyptic number.

390945866 is a deficient number, since it is larger than the sum of its proper divisors (195472936).

390945866 is a wasteful number, since it uses less digits than its factorization.

390945866 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 195472935.

The product of its (nonzero) digits is 1399680, while the sum is 50.

The square root of 390945866 is about 19772.3510488763. The cubic root of 390945866 is about 731.2045329219.

The spelling of 390945866 in words is "three hundred ninety million, nine hundred forty-five thousand, eight hundred sixty-six".