21565647949848 has 32 divisors (see below), whose sum is σ = 53914364900160. Its totient is φ = 7188516646560.

The previous prime is 21565647949831. The next prime is 21565647949861. The reversal of 21565647949848 is 84894974656512.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3675711 + ... + 7526097.

It is an arithmetic number, because the mean of its divisors is an integer number (1684823903130).

Almost surely, 2^{21565647949848} is an apocalyptic number.

It is an amenable number.

21565647949848 is an abundant number, since it is smaller than the sum of its proper divisors (32348716950312).

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

21565647949848 is a wasteful number, since it uses less digits than its factorization.

21565647949848 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4083767 (or 4083763 counting only the distinct ones).

The product of its digits is 4180377600, while the sum is 78.

The spelling of 21565647949848 in words is "twenty-one trillion, five hundred sixty-five billion, six hundred forty-seven million, nine hundred forty-nine thousand, eight hundred forty-eight".