21660479262724 has 81 divisors (see below), whose sum is σ = 39386962922013. Its totient is φ = 10422760790016.

The previous prime is 21660479262703. The next prime is 21660479262743. The reversal of 21660479262724 is 42726297406612.

The square root of 21660479262724 is 4654082.

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

It can be written as a sum of positive squares in 13 ways, for example, as 6392391909124 + 15268087353600 = 2528318^2 + 3907440^2 .

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 37539825124 + ... + 37539825700.

Almost surely, 2^{21660479262724} is an apocalyptic number.

21660479262724 is the 4654082-nd square number.

It is an amenable number.

21660479262724 is a deficient number, since it is larger than the sum of its proper divisors (17726483659289).

21660479262724 is an frugal number, since it uses more digits than its factorization.

21660479262724 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1450 (or 725 counting only the distinct ones).

The product of its (nonzero) digits is 24385536, while the sum is 58.

The spelling of 21660479262724 in words is "twenty-one trillion, six hundred sixty billion, four hundred seventy-nine million, two hundred sixty-two thousand, seven hundred twenty-four".