399661667344 has 15 divisors (see below), whose sum is σ = 774349379967. Its totient is φ = 199829569296.

The previous prime is 399661667333. The next prime is 399661667347. The reversal of 399661667344 is 443766166993.

The square root of 399661667344 is 632188.

It is a perfect power (a square), and thus also a powerful number.

It is a super-2 number, since 2×399661667344² (a number of 24 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (399661667347) by changing a digit.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 2449729 + ... + 2607775.

Almost surely, 2^399661667344 is an apocalyptic number.

399661667344 is the 632188-th square number.

It is an amenable number.

399661667344 is a deficient number, since it is larger than the sum of its proper divisors (374687712623).

399661667344 is an frugal number, since it uses more digits than its factorization.

399661667344 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 316102 (or 158049 counting only the distinct ones).

The product of its digits is 105815808, while the sum is 64.

Multiplying 399661667344 by its sum of digits (64), we get a square (25578346710016 = 5057504²).

The spelling of 399661667344 in words is "three hundred ninety-nine billion, six hundred sixty-one million, six hundred sixty-seven thousand, three hundred forty-four".