21504360664611 has 24 divisors (see below), whose sum is σ = 35140683649344. Its totient is φ = 13032945855720.

The previous prime is 21504360664603. The next prime is 21504360664637. The reversal of 21504360664611 is 11646606340512.

21504360664611 is a `hidden beast` number, since 2 + 1 + 504 + 36 + 0 + 66 + 46 + 11 = 666.

It is not a de Polignac number, because 21504360664611 - 2³ = 21504360664603 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21504360662611) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 4022511481 + ... + 4022516826.

It is an arithmetic number, because the mean of its divisors is an integer number (1464195152056).

Almost surely, 2^{21504360664611} is an apocalyptic number.

21504360664611 is a deficient number, since it is larger than the sum of its proper divisors (13636322984733).

21504360664611 is an equidigital number, since it uses as much as digits as its factorization.

21504360664611 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8045028333 (or 8045028321 counting only the distinct ones).

The product of its (nonzero) digits is 622080, while the sum is 45.

The spelling of 21504360664611 in words is "twenty-one trillion, five hundred four billion, three hundred sixty million, six hundred sixty-four thousand, six hundred eleven".