399521163 has 4 divisors (see below), whose sum is σ = 532694888. Its totient is φ = 266347440.

The previous prime is 399521159. The next prime is 399521173. The reversal of 399521163 is 361125993.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 361125993 = 3 ⋅120375331.

It is not a de Polignac number, because 399521163 - 2² = 399521159 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (399521173) 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, 66586858 + ... + 66586863.

It is an arithmetic number, because the mean of its divisors is an integer number (133173722).

Almost surely, 2^399521163 is an apocalyptic number.

399521163 is a deficient number, since it is larger than the sum of its proper divisors (133173725).

399521163 is a wasteful number, since it uses less digits than its factorization.

399521163 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 133173724.

The product of its digits is 43740, while the sum is 39.

The square root of 399521163 is about 19988.0254902779. The cubic root of 399521163 is about 736.5121738998.

The spelling of 399521163 in words is "three hundred ninety-nine million, five hundred twenty-one thousand, one hundred sixty-three".