399917947 has 24 divisors (see below), whose sum is σ = 498345680. Its totient is φ = 317908800.

The previous prime is 399917939. The next prime is 399917953. The reversal of 399917947 is 749719993.

It is not a de Polignac number, because 399917947 - 2³ = 399917939 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 399917891 and 399917900.

It is not an unprimeable number, because it can be changed into a prime (399917927) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 23197 + ... + 36577.

Almost surely, 2^399917947 is an apocalyptic number.

399917947 is a deficient number, since it is larger than the sum of its proper divisors (98427733).

399917947 is a wasteful number, since it uses less digits than its factorization.

399917947 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13435 (or 13424 counting only the distinct ones).

The product of its digits is 3857868, while the sum is 58.

The square root of 399917947 is about 19997.9485697909. The cubic root of 399917947 is about 736.7559153100.

The spelling of 399917947 in words is "three hundred ninety-nine million, nine hundred seventeen thousand, nine hundred forty-seven".