399652816761 has 27 divisors (see below), whose sum is σ = 634559956303. Its totient is φ = 242201184720.

The previous prime is 399652816753. The next prime is 399652816789. The reversal of 399652816761 is 167618256993.

The square root of 399652816761 is 632181.

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

399652816761 is a `hidden beast` number, since 3 + 9 + 96 + 528 + 16 + 7 + 6 + 1 = 666.

It can be written as a sum of positive squares in only one way, i.e., 11967266025 + 387685550736 = 109395^2 + 622644^2 .

It is not a de Polignac number, because 399652816761 - 2³ = 399652816753 is a prime.

It is a super-2 number, since 2×399652816761² (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 (399652816721) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 20852395 + ... + 20871551.

Almost surely, 2^399652816761 is an apocalyptic number.

399652816761 is the 632181-st square number.

399652816761 is the 316091-st centered octagonal number.

It is an amenable number.

399652816761 is a deficient number, since it is larger than the sum of its proper divisors (234907139542).

399652816761 is an frugal number, since it uses more digits than its factorization.

399652816761 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 38342 (or 19171 counting only the distinct ones).

The product of its digits is 29393280, while the sum is 63.

The spelling of 399652816761 in words is "three hundred ninety-nine billion, six hundred fifty-two million, eight hundred sixteen thousand, seven hundred sixty-one".