399936161 has 4 divisors (see below), whose sum is σ = 406714800. Its totient is φ = 393157524.

The previous prime is 399936133. The next prime is 399936211. The reversal of 399936161 is 161639993.

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, and also an emirpimes, since its reverse is a distinct semiprime: 161639993 = 1423 ⋅113591.

It is a cyclic number.

It is not a de Polignac number, because 399936161 - 2¹⁸ = 399674017 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (399936661) 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, 3389231 + ... + 3389348.

It is an arithmetic number, because the mean of its divisors is an integer number (101678700).

Almost surely, 2^399936161 is an apocalyptic number.

It is an amenable number.

399936161 is a deficient number, since it is larger than the sum of its proper divisors (6778639).

399936161 is an equidigital number, since it uses as much as digits as its factorization.

399936161 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6778638.

The product of its digits is 236196, while the sum is 47.

The square root of 399936161 is about 19998.4039613165. The cubic root of 399936161 is about 736.7671001615.

The spelling of 399936161 in words is "three hundred ninety-nine million, nine hundred thirty-six thousand, one hundred sixty-one".