399565580544 has 243 divisors, whose sum is σ = 1248714530427. Its totient is φ = 122821890048.

The previous prime is 399565580503. The next prime is 399565580551. The reversal of 399565580544 is 445085565993.

The square root of 399565580544 is 632112.

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

399565580544 is a `hidden beast` number, since 3 + 9 + 9 + 5 + 6 + 5 + 5 + 80 + 544 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 327312140544 + 72253440000 = 572112^2 + 268800^2 .

It is an unprimeable number.

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, 394437382 + ... + 394438394.

Almost surely, 2^399565580544 is an apocalyptic number.

399565580544 is the 632112-nd square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 399565580544

399565580544 is an abundant number, since it is smaller than the sum of its proper divisors (849148949883).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

399565580544 is an equidigital number, since it uses as much as digits as its factorization.

399565580544 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2074 (or 1031 counting only the distinct ones).

The product of its (nonzero) digits is 116640000, while the sum is 63.

The spelling of 399565580544 in words is "three hundred ninety-nine billion, five hundred sixty-five million, five hundred eighty thousand, five hundred forty-four".