21402984784896 has 891 divisors, whose sum is σ = 73775869989003. Its totient is φ = 5969083760640.

The previous prime is 21402984784793. The next prime is 21402984784913. The reversal of 21402984784896 is 69848748920412.

It is a happy number.

The square root of 21402984784896 is 4626336.

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

21402984784896 is a `hidden beast` number, since 2 + 1 + 4 + 0 + 29 + 8 + 478 + 48 + 96 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 7428546487296 + 13974438297600 = 2725536^2 + 3738240^2 .

It is a super-3 number, since 3×21402984784896³ (a number of 41 digits) contains 333 as substring.

It is a Harshad number since it is a multiple of its sum of digits (72).

It is an unprimeable number.

It is a polite number, since it can be written in 80 ways as a sum of consecutive naturals, for example, 63510340440 + ... + 63510340776.

Almost surely, 2^{21402984784896} is an apocalyptic number.

21402984784896 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

21402984784896 is the 4626336-th square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21402984784896

21402984784896 is an abundant number, since it is smaller than the sum of its proper divisors (52372885204107).

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

21402984784896 is a wasteful number, since it uses less digits than its factorization.

21402984784896 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 748 (or 366 counting only the distinct ones).

The product of its (nonzero) digits is 445906944, while the sum is 72.

The spelling of 21402984784896 in words is "twenty-one trillion, four hundred two billion, nine hundred eighty-four million, seven hundred eighty-four thousand, eight hundred ninety-six".