21365361647055 has 24 divisors (see below), whose sum is σ = 37052898377040. Its totient is φ = 11388827281920.

The previous prime is 21365361647039. The next prime is 21365361647093. The reversal of 21365361647055 is 55074616356312.

21365361647055 is a `hidden beast` number, since 2 + 1 + 3 + 6 + 536 + 16 + 47 + 0 + 55 = 666.

It is not a de Polignac number, because 21365361647055 - 2⁴ = 21365361647039 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21365361646992 and 21365361647010.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 125586201 + ... + 125756210.

It is an arithmetic number, because the mean of its divisors is an integer number (1543870765710).

Almost surely, 2^{21365361647055} is an apocalyptic number.

21365361647055 is a deficient number, since it is larger than the sum of its proper divisors (15687536729985).

21365361647055 is a wasteful number, since it uses less digits than its factorization.

21365361647055 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 251344311 (or 251344308 counting only the distinct ones).

The product of its (nonzero) digits is 13608000, while the sum is 54.

The spelling of 21365361647055 in words is "twenty-one trillion, three hundred sixty-five billion, three hundred sixty-one million, six hundred forty-seven thousand, fifty-five".