21530698560 has 896 divisors, whose sum is σ = 94243184640. Its totient is φ = 4514807808.

The previous prime is 21530698537. The next prime is 21530698561. The reversal of 21530698560 is 6589603512.

21530698560 is a `hidden beast` number, since 2 + 1 + 530 + 69 + 8 + 56 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21530698561) by changing a digit.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 44210637 + ... + 44211123.

Almost surely, 2^21530698560 is an apocalyptic number.

21530698560 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 21530698560, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (47121592320).

21530698560 is an abundant number, since it is smaller than the sum of its proper divisors (72712486080).

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

21530698560 is a wasteful number, since it uses less digits than its factorization.

21530698560 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 580 (or 564 counting only the distinct ones).

The product of its (nonzero) digits is 388800, while the sum is 45.

The spelling of 21530698560 in words is "twenty-one billion, five hundred thirty million, six hundred ninety-eight thousand, five hundred sixty".