21394327824 has 225 divisors, whose sum is σ = 66054461077. Its totient is φ = 6683862528.

The previous prime is 21394327819. The next prime is 21394327891. The reversal of 21394327824 is 42872349312.

The square root of 21394327824 is 146268.

It is a perfect power (a square), and thus also a powerful number.

21394327824 is a `hidden beast` number, since 2 + 139 + 432 + 7 + 82 + 4 = 666.

It can be written as a sum of positive squares in only one way, i.e., 16656483600 + 4737844224 = 129060^2 + 68832^2 .

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21394327824.

It is an unprimeable number.

It is a polite number, since it can be written in 44 ways as a sum of consecutive naturals, for example, 89515897 + ... + 89516135.

Almost surely, 2^21394327824 is an apocalyptic number.

21394327824 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

21394327824 is the 146268-th square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21394327824

21394327824 is an abundant number, since it is smaller than the sum of its proper divisors (44660133253).

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

21394327824 is an equidigital number, since it uses as much as digits as its factorization.

21394327824 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 532 (or 261 counting only the distinct ones).

The product of its digits is 580608, while the sum is 45.

The spelling of 21394327824 in words is "twenty-one billion, three hundred ninety-four million, three hundred twenty-seven thousand, eight hundred twenty-four".