21365063163565 has 16 divisors (see below), whose sum is σ = 28933251684480. Its totient is φ = 15002426797120.

The previous prime is 21365063163541. The next prime is 21365063163593. The reversal of 21365063163565 is 56536136056312.

It is not a de Polignac number, because 21365063163565 - 2¹⁵ = 21365063130797 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 6697510369 + ... + 6697513558.

It is an arithmetic number, because the mean of its divisors is an integer number (1808328230280).

Almost surely, 2^{21365063163565} is an apocalyptic number.

It is an amenable number.

21365063163565 is a deficient number, since it is larger than the sum of its proper divisors (7568188520915).

21365063163565 is a wasteful number, since it uses less digits than its factorization.

21365063163565 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13395023972.

The product of its (nonzero) digits is 8748000, while the sum is 52.

The spelling of 21365063163565 in words is "twenty-one trillion, three hundred sixty-five billion, sixty-three million, one hundred sixty-three thousand, five hundred sixty-five".