399944018 has 4 divisors (see below), whose sum is σ = 599916030. Its totient is φ = 199972008.

The previous prime is 399944011. The next prime is 399944021. The reversal of 399944018 is 810449993.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 399880009 + 64009 = 19997^2 + 253^2 .

It is not an unprimeable number, because it can be changed into a prime (399944011) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 99986003 + ... + 99986006.

Almost surely, 2^399944018 is an apocalyptic number.

399944018 is a deficient number, since it is larger than the sum of its proper divisors (199972012).

399944018 is a wasteful number, since it uses less digits than its factorization.

399944018 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 199972011.

The product of its (nonzero) digits is 279936, while the sum is 47.

The square root of 399944018 is about 19998.6004010281. The cubic root of 399944018 is about 736.7719248825.

The spelling of 399944018 in words is "three hundred ninety-nine million, nine hundred forty-four thousand, eighteen".