399805649 has 8 divisors (see below), whose sum is σ = 405452160. Its totient is φ = 394173936.

The previous prime is 399805631. The next prime is 399805691. The reversal of 399805649 is 946508993.

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

It is a cyclic number.

It is not a de Polignac number, because 399805649 - 2²⁸ = 131370193 is a prime.

It is a super-2 number, since 2×399805649² = 319689113944622402, which contains 22 as substring.

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 399805649.

It is not an unprimeable number, because it can be changed into a prime (399805699) 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, 57794 + ... + 64340.

It is an arithmetic number, because the mean of its divisors is an integer number (50681520).

Almost surely, 2^399805649 is an apocalyptic number.

It is an amenable number.

399805649 is a deficient number, since it is larger than the sum of its proper divisors (5646511).

399805649 is an equidigital number, since it uses as much as digits as its factorization.

399805649 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7399.

The product of its (nonzero) digits is 2099520, while the sum is 53.

The square root of 399805649 is about 19995.1406346642. The cubic root of 399805649 is about 736.6869478616.

The spelling of 399805649 in words is "three hundred ninety-nine million, eight hundred five thousand, six hundred forty-nine".