399581161 has 4 divisors (see below), whose sum is σ = 456664192. Its totient is φ = 342498132.

The previous prime is 399581137. The next prime is 399581177. The reversal of 399581161 is 161185993.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 399581161 - 2⁵ = 399581129 is a prime.

It is a super-2 number, since 2×399581161² = 319330208452215842, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (399581101) 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, 28541505 + ... + 28541518.

It is an arithmetic number, because the mean of its divisors is an integer number (114166048).

Almost surely, 2^399581161 is an apocalyptic number.

It is an amenable number.

399581161 is a deficient number, since it is larger than the sum of its proper divisors (57083031).

399581161 is an equidigital number, since it uses as much as digits as its factorization.

399581161 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 57083030.

The product of its digits is 58320, while the sum is 43.

The square root of 399581161 is about 19989.5262825311. The cubic root of 399581161 is about 736.5490405706.

The spelling of 399581161 in words is "three hundred ninety-nine million, five hundred eighty-one thousand, one hundred sixty-one".