21524451264 has 168 divisors, whose sum is σ = 68763885840. Its totient is φ = 6397304832.

The previous prime is 21524451259. The next prime is 21524451313. The reversal of 21524451264 is 46215442512.

21524451264 is a `hidden beast` number, since 2 + 1 + 524 + 4 + 5 + 126 + 4 = 666.

It is a super-2 number, since 2×21524451264² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 128202 + ... + 243894.

Almost surely, 2^21524451264 is an apocalyptic number.

21524451264 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21524451264, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34381942920).

21524451264 is an abundant number, since it is smaller than the sum of its proper divisors (47239434576).

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

21524451264 is a wasteful number, since it uses less digits than its factorization.

21524451264 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 115747 (or 115734 counting only the distinct ones).

The product of its digits is 76800, while the sum is 36.

Adding to 21524451264 its reverse (46215442512), we get a palindrome (67739893776).

The spelling of 21524451264 in words is "twenty-one billion, five hundred twenty-four million, four hundred fifty-one thousand, two hundred sixty-four".