21636142216400 has 30 divisors (see below), whose sum is σ = 51980831675862. Its totient is φ = 8654456886400.

The previous prime is 21636142216373. The next prime is 21636142216499. The reversal of 21636142216400 is 461224163612.

It can be written as a sum of positive squares in 3 ways, for example, as 130069865104 + 21506072351296 = 360652^2 + 4637464^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 27045177371 + ... + 27045178170.

Almost surely, 2^{21636142216400} is an apocalyptic number.

21636142216400 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21636142216400 is an abundant number, since it is smaller than the sum of its proper divisors (30344689459462).

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

21636142216400 is a wasteful number, since it uses less digits than its factorization.

21636142216400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 54090355559 (or 54090355548 counting only the distinct ones).

The product of its (nonzero) digits is 82944, while the sum is 38.

The spelling of 21636142216400 in words is "twenty-one trillion, six hundred thirty-six billion, one hundred forty-two million, two hundred sixteen thousand, four hundred".