21609960624 has 320 divisors, whose sum is σ = 75709440000. Its totient is φ = 5768340480.

The previous prime is 21609960611. The next prime is 21609960649. The reversal of 21609960624 is 42606990612.

21609960624 is a `hidden beast` number, since 2 + 16 + 0 + 9 + 9 + 6 + 0 + 624 = 666.

It is a self number, because there is not a number n which added to its sum of digits gives 21609960624.

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 63 ways as a sum of consecutive naturals, for example, 2714602 + ... + 2722550.

It is an arithmetic number, because the mean of its divisors is an integer number (236592000).

Almost surely, 2^21609960624 is an apocalyptic number.

21609960624 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 21609960624, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (37854720000).

21609960624 is an abundant number, since it is smaller than the sum of its proper divisors (54099479376).

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

21609960624 is a wasteful number, since it uses less digits than its factorization.

21609960624 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8033 (or 8021 counting only the distinct ones).

The product of its (nonzero) digits is 279936, while the sum is 45.

The spelling of 21609960624 in words is "twenty-one billion, six hundred nine million, nine hundred sixty thousand, six hundred twenty-four".