21580457472 has 240 divisors, whose sum is σ = 72840218880. Its totient is φ = 6022066176.

The previous prime is 21580457447. The next prime is 21580457489. The reversal of 21580457472 is 27475408512.

21580457472 is a `hidden beast` number, since 2 + 1 + 5 + 8 + 0 + 4 + 574 + 72 = 666.

It is a super-2 number, since 2×21580457472² (a number of 21 digits) contains 22 as substring.

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, 1379229 + ... + 1394787.

It is an arithmetic number, because the mean of its divisors is an integer number (303500912).

Almost surely, 2^21580457472 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21580457472, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (36420109440).

21580457472 is an abundant number, since it is smaller than the sum of its proper divisors (51259761408).

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

21580457472 is a wasteful number, since it uses less digits than its factorization.

21580457472 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15633 (or 15614 counting only the distinct ones).

The product of its (nonzero) digits is 627200, while the sum is 45.

The spelling of 21580457472 in words is "twenty-one billion, five hundred eighty million, four hundred fifty-seven thousand, four hundred seventy-two".