21527267664 has 160 divisors (see below), whose sum is σ = 64349381376. Its totient is φ = 6074265600.

The previous prime is 21527267599. The next prime is 21527267687. The reversal of 21527267664 is 46676272512.

It is a super-4 number, since 4×21527267664⁴ (a number of 42 digits) contains 4444 as substring.

It is a Harshad number since it is a multiple of its sum of digits (48).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 22974204 + ... + 22975140.

Almost surely, 2^21527267664 is an apocalyptic number.

21527267664 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 21527267664, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32174690688).

21527267664 is an abundant number, since it is smaller than the sum of its proper divisors (42822113712).

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

21527267664 is a wasteful number, since it uses less digits than its factorization.

21527267664 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1733 (or 1727 counting only the distinct ones).

The product of its digits is 1693440, while the sum is 48.

The spelling of 21527267664 in words is "twenty-one billion, five hundred twenty-seven million, two hundred sixty-seven thousand, six hundred sixty-four".