21227507280 has 480 divisors, whose sum is σ = 85437031680. Its totient is φ = 4621639680.

The previous prime is 21227507243. The next prime is 21227507297. The reversal of 21227507280 is 8270572212.

21227507280 is a `hidden beast` number, since 2 + 122 + 7 + 507 + 28 + 0 = 666.

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

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 8884326 + ... + 8886714.

It is an arithmetic number, because the mean of its divisors is an integer number (177993816).

Almost surely, 2^21227507280 is an apocalyptic number.

21227507280 is a gapful number since it is divisible by the number (20) 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 21227507280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (42718515840).

21227507280 is an abundant number, since it is smaller than the sum of its proper divisors (64209524400).

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

21227507280 is a wasteful number, since it uses less digits than its factorization.

21227507280 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2499 (or 2490 counting only the distinct ones).

The product of its (nonzero) digits is 31360, while the sum is 36.

The spelling of 21227507280 in words is "twenty-one billion, two hundred twenty-seven million, five hundred seven thousand, two hundred eighty".