399705537 has 32 divisors (see below), whose sum is σ = 685891584. Its totient is φ = 200937600.

The previous prime is 399705533. The next prime is 399705563. The reversal of 399705537 is 735507993.

It is not a de Polignac number, because 399705537 - 2² = 399705533 is a prime.

It is not an unprimeable number, because it can be changed into a prime (399705533) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 20748 + ... + 35069.

It is an arithmetic number, because the mean of its divisors is an integer number (21434112).

Almost surely, 2^399705537 is an apocalyptic number.

It is an amenable number.

399705537 is a deficient number, since it is larger than the sum of its proper divisors (286186047).

399705537 is a wasteful number, since it uses less digits than its factorization.

399705537 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 55869.

The product of its (nonzero) digits is 893025, while the sum is 48.

The square root of 399705537 is about 19992.6370696814. The cubic root of 399705537 is about 736.6254535159.

The spelling of 399705537 in words is "three hundred ninety-nine million, seven hundred five thousand, five hundred thirty-seven".