399748609 has 8 divisors (see below), whose sum is σ = 430899560. Its totient is φ = 368654976.

The previous prime is 399748603. The next prime is 399748637. The reversal of 399748609 is 906847993.

It can be written as a sum of positive squares in 4 ways, for example, as 10870209 + 388878400 = 3297^2 + 19720^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-399748609 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 399748609.

It is not an unprimeable number, because it can be changed into a prime (399748603) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 757 + ... + 28285.

It is an arithmetic number, because the mean of its divisors is an integer number (53862445).

Almost surely, 2^399748609 is an apocalyptic number.

It is an amenable number.

399748609 is a deficient number, since it is larger than the sum of its proper divisors (31150951).

399748609 is a wasteful number, since it uses less digits than its factorization.

399748609 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 28659.

The product of its (nonzero) digits is 2939328, while the sum is 55.

The square root of 399748609 is about 19993.7142372297. The cubic root of 399748609 is about 736.6519119867.

The spelling of 399748609 in words is "three hundred ninety-nine million, seven hundred forty-eight thousand, six hundred nine".