399616649 has 4 divisors (see below), whose sum is σ = 399789264. Its totient is φ = 399444036.

The previous prime is 399616643. The next prime is 399616663. The reversal of 399616649 is 946616993.

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 399616649 - 2¹² = 399612553 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 399616649.

It is not an unprimeable number, because it can be changed into a prime (399616643) 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, 82787 + ... + 87480.

It is an arithmetic number, because the mean of its divisors is an integer number (99947316).

Almost surely, 2^399616649 is an apocalyptic number.

It is an amenable number.

399616649 is a deficient number, since it is larger than the sum of its proper divisors (172615).

399616649 is a wasteful number, since it uses less digits than its factorization.

399616649 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 172614.

The product of its digits is 1889568, while the sum is 53.

The square root of 399616649 is about 19990.4139276804. The cubic root of 399616649 is about 736.5708449674.

The spelling of 399616649 in words is "three hundred ninety-nine million, six hundred sixteen thousand, six hundred forty-nine".