21504715264 has 20 divisors (see below), whose sum is σ = 42967430154. Its totient is φ = 10752357376.

The previous prime is 21504715259. The next prime is 21504715307. The reversal of 21504715264 is 46251740512.

It can be written as a sum of positive squares in only one way, i.e., 15515193600 + 5989521664 = 124560^2 + 77392^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21000187 + ... + 21001210.

Almost surely, 2^21504715264 is an apocalyptic number.

It is an amenable number.

21504715264 is a deficient number, since it is larger than the sum of its proper divisors (21462714890).

21504715264 is an frugal number, since it uses more digits than its factorization.

21504715264 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 42001415 (or 42001399 counting only the distinct ones).

The product of its (nonzero) digits is 67200, while the sum is 37.

The spelling of 21504715264 in words is "twenty-one billion, five hundred four million, seven hundred fifteen thousand, two hundred sixty-four".