21365564501465 has 8 divisors (see below), whose sum is σ = 25638745651008. Its totient is φ = 17092406101680.

The previous prime is 21365564501419. The next prime is 21365564501539. The reversal of 21365564501465 is 56410546556312.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21365564501465 - 2¹⁴ = 21365564485081 is a prime.

It is a super-3 number, since 3×21365564501465³ (a number of 41 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3548141 + ... + 7437770.

It is an arithmetic number, because the mean of its divisors is an integer number (3204843206376).

Almost surely, 2^{21365564501465} is an apocalyptic number.

It is an amenable number.

21365564501465 is a deficient number, since it is larger than the sum of its proper divisors (4273181149543).

21365564501465 is a wasteful number, since it uses less digits than its factorization.

21365564501465 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11374879.

The product of its (nonzero) digits is 12960000, while the sum is 53.

The spelling of 21365564501465 in words is "twenty-one trillion, three hundred sixty-five billion, five hundred sixty-four million, five hundred one thousand, four hundred sixty-five".