21860594420 has 54 divisors (see below), whose sum is σ = 53413618482. Its totient is φ = 7493474016.

The previous prime is 21860594411. The next prime is 21860594479. The reversal of 21860594420 is 2449506812.

It can be written as a sum of positive squares in only one way, i.e., 17488475536 + 4372118884 = 132244^2 + 66122^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 4626179 + ... + 4630901.

It is an arithmetic number, because the mean of its divisors is an integer number (989141083).

Almost surely, 2^21860594420 is an apocalyptic number.

21860594420 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21860594420 is an abundant number, since it is smaller than the sum of its proper divisors (31553024062).

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

21860594420 is an frugal number, since it uses more digits than its factorization.

21860594420 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9469 (or 4737 counting only the distinct ones).

The product of its (nonzero) digits is 138240, while the sum is 41.

The spelling of 21860594420 in words is "twenty-one billion, eight hundred sixty million, five hundred ninety-four thousand, four hundred twenty".