399219657 has 16 divisors (see below), whose sum is σ = 538462080. Its totient is φ = 263071872.

The previous prime is 399219649. The next prime is 399219661. The reversal of 399219657 is 756912993.

It is a happy number.

It is not a de Polignac number, because 399219657 - 2³ = 399219649 is a prime.

It is not an unprimeable number, because it can be changed into a prime (399219617) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 249183 + ... + 250779.

It is an arithmetic number, because the mean of its divisors is an integer number (33653880).

Almost surely, 2^399219657 is an apocalyptic number.

It is an amenable number.

399219657 is a deficient number, since it is larger than the sum of its proper divisors (139242423).

399219657 is a wasteful number, since it uses less digits than its factorization.

399219657 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2512.

The product of its digits is 918540, while the sum is 51.

The square root of 399219657 is about 19980.4819010954. The cubic root of 399219657 is about 736.3268531168.

The spelling of 399219657 in words is "three hundred ninety-nine million, two hundred nineteen thousand, six hundred fifty-seven".