399157937 has 4 divisors (see below), whose sum is σ = 400814436. Its totient is φ = 397501440.

The previous prime is 399157933. The next prime is 399157987. The reversal of 399157937 is 739751993.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 739751993 = 21569 ⋅34297.

It can be written as a sum of positive squares in 2 ways, for example, as 120802081 + 278355856 = 10991^2 + 16684^2 .

It is a cyclic number.

It is not a de Polignac number, because 399157937 - 2² = 399157933 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (399157933) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 827888 + ... + 828369.

It is an arithmetic number, because the mean of its divisors is an integer number (100203609).

Almost surely, 2^399157937 is an apocalyptic number.

It is an amenable number.

399157937 is a deficient number, since it is larger than the sum of its proper divisors (1656499).

399157937 is a wasteful number, since it uses less digits than its factorization.

399157937 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1656498.

The product of its digits is 1607445, while the sum is 53.

The square root of 399157937 is about 19978.9373341026. The cubic root of 399157937 is about 736.2889053899.

The spelling of 399157937 in words is "three hundred ninety-nine million, one hundred fifty-seven thousand, nine hundred thirty-seven".