21368966984964 has 243 divisors, whose sum is σ = 57873199950111. Its totient is φ = 6647752016640.

The previous prime is 21368966984947. The next prime is 21368966984977. The reversal of 21368966984964 is 46948966986312.

The square root of 21368966984964 is 4622658.

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

21368966984964 is a `hidden beast` number, since 2 + 1 + 3 + 68 + 9 + 6 + 69 + 8 + 496 + 4 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 5566815548100 + 15802151436864 = 2359410^2 + 3975192^2 .

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, 24934616824 + ... + 24934617680.

Almost surely, 2^{21368966984964} is an apocalyptic number.

21368966984964 is the 4622658-th square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21368966984964

21368966984964 is an abundant number, since it is smaller than the sum of its proper divisors (36504232965147).

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

21368966984964 is an equidigital number, since it uses as much as digits as its factorization.

21368966984964 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1844 (or 922 counting only the distinct ones).

The product of its digits is 5804752896, while the sum is 81.

The spelling of 21368966984964 in words is "twenty-one trillion, three hundred sixty-eight billion, nine hundred sixty-six million, nine hundred eighty-four thousand, nine hundred sixty-four".