21812594020 has 36 divisors (see below), whose sum is σ = 53285053500. Its totient is φ = 7478603328.

The previous prime is 21812594009. The next prime is 21812594059. The reversal of 21812594020 is 2049521812.

It can be written as a sum of positive squares in 2 ways, for example, as 10107085156 + 11705508864 = 100534^2 + 108192^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 11127895 + ... + 11129854.

It is an arithmetic number, because the mean of its divisors is an integer number (1480140375).

Almost surely, 2^21812594020 is an apocalyptic number.

21812594020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21812594020 is an abundant number, since it is smaller than the sum of its proper divisors (31472459480).

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

21812594020 is a wasteful number, since it uses less digits than its factorization.

21812594020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22257772 (or 22257763 counting only the distinct ones).

The product of its (nonzero) digits is 11520, while the sum is 34.

The spelling of 21812594020 in words is "twenty-one billion, eight hundred twelve million, five hundred ninety-four thousand, twenty".