21284086824 has 960 divisors, whose sum is σ = 85434518400. Its totient is φ = 4803701760.

The previous prime is 21284086807. The next prime is 21284086849. The reversal of 21284086824 is 42868048212.

21284086824 is a `hidden beast` number, since 212 + 8 + 408 + 6 + 8 + 24 = 666.

It is a self number, because there is not a number n which added to its sum of digits gives 21284086824.

It is an unprimeable number.

It is a polite number, since it can be written in 239 ways as a sum of consecutive naturals, for example, 135567354 + ... + 135567510.

It is an arithmetic number, because the mean of its divisors is an integer number (88994290).

Almost surely, 2^21284086824 is an apocalyptic number.

21284086824 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 21284086824, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (42717259200).

21284086824 is an abundant number, since it is smaller than the sum of its proper divisors (64150431576).

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

21284086824 is a wasteful number, since it uses less digits than its factorization.

21284086824 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 236 (or 212 counting only the distinct ones).

The product of its (nonzero) digits is 393216, while the sum is 45.

The spelling of 21284086824 in words is "twenty-one billion, two hundred eighty-four million, eighty-six thousand, eight hundred twenty-four".