399729644 has 6 divisors (see below), whose sum is σ = 699526884. Its totient is φ = 199864820.

The previous prime is 399729643. The next prime is 399729679. The reversal of 399729644 is 446927993.

It is not an unprimeable number, because it can be changed into a prime (399729641) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 49966202 + ... + 49966209.

It is an arithmetic number, because the mean of its divisors is an integer number (116587814).

Almost surely, 2^399729644 is an apocalyptic number.

It is an amenable number.

399729644 is a deficient number, since it is larger than the sum of its proper divisors (299797240).

399729644 is a wasteful number, since it uses less digits than its factorization.

399729644 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 99932415 (or 99932413 counting only the distinct ones).

The product of its digits is 2939328, while the sum is 53.

The square root of 399729644 is about 19993.2399575457. The cubic root of 399729644 is about 736.6402623115.

The spelling of 399729644 in words is "three hundred ninety-nine million, seven hundred twenty-nine thousand, six hundred forty-four".