21523237264 has 15 divisors (see below), whose sum is σ = 41702409217. Its totient is φ = 10761325216.

The previous prime is 21523237201. The next prime is 21523237273. The reversal of 21523237264 is 46273232512.

The square root of 21523237264 is 146708.

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

It can be written as a sum of positive squares in only one way, i.e., 21065619600 + 457617664 = 145140^2 + 21392^2 .

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 568494 + ... + 605170.

Almost surely, 2^21523237264 is an apocalyptic number.

21523237264 is the 146708-th square number.

It is an amenable number.

21523237264 is a deficient number, since it is larger than the sum of its proper divisors (20179171953).

21523237264 is an frugal number, since it uses more digits than its factorization.

21523237264 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 73362 (or 36679 counting only the distinct ones).

The product of its digits is 120960, while the sum is 37.

Adding to 21523237264 its reverse (46273232512), we get a palindrome (67796469776).

The spelling of 21523237264 in words is "twenty-one billion, five hundred twenty-three million, two hundred thirty-seven thousand, two hundred sixty-four".