21645844792848 has 60 divisors (see below), whose sum is σ = 60587431783788. Its totient is φ = 7214194149120.

The previous prime is 21645844792841. The next prime is 21645844792883. The reversal of 21645844792848 is 84829744854612.

21645844792848 is a `hidden beast` number, since 2 + 1 + 6 + 4 + 58 + 447 + 92 + 8 + 48 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 9197706003984 + 12448138788864 = 3032772^2 + 3528192^2 .

It is a super-2 number, since 2×21645844792848² (a number of 27 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (72).

It is not an unprimeable number, because it can be changed into a prime (21645844792841) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 10368543 + ... + 12279998.

Almost surely, 2^{21645844792848} is an apocalyptic number.

It is an amenable number.

21645844792848 is an abundant number, since it is smaller than the sum of its proper divisors (38941586990940).

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

21645844792848 is a wasteful number, since it uses less digits than its factorization.

21645844792848 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22655192 (or 22655183 counting only the distinct ones).

The product of its digits is 990904320, while the sum is 72.

The spelling of 21645844792848 in words is "twenty-one trillion, six hundred forty-five billion, eight hundred forty-four million, seven hundred ninety-two thousand, eight hundred forty-eight".