399649657 has 8 divisors (see below), whose sum is σ = 443371680. Its totient is φ = 357159360.

The previous prime is 399649639. The next prime is 399649661. The reversal of 399649657 is 756946993.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-399649657 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (399649157) 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 in 7 ways as a sum of consecutive naturals, for example, 307248 + ... + 308545.

It is an arithmetic number, because the mean of its divisors is an integer number (55421460).

Almost surely, 2^399649657 is an apocalyptic number.

It is an amenable number.

399649657 is a deficient number, since it is larger than the sum of its proper divisors (43722023).

399649657 is a wasteful number, since it uses less digits than its factorization.

399649657 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 615863.

The product of its digits is 11022480, while the sum is 58.

The square root of 399649657 is about 19991.2395063438. The cubic root of 399649657 is about 736.5911244537.

It can be divided in two parts, 399 and 649657, that added together give a palindrome (650056).

The spelling of 399649657 in words is "three hundred ninety-nine million, six hundred forty-nine thousand, six hundred fifty-seven".