21083591620 has 108 divisors (see below), whose sum is σ = 55771260804. Its totient is φ = 6672556800.

The previous prime is 21083591611. The next prime is 21083591621. The reversal of 21083591620 is 2619538012.

It can be written as a sum of positive squares in 6 ways, for example, as 4623728004 + 16459863616 = 67998^2 + 128296^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 21083591620.

It is not an unprimeable number, because it can be changed into a prime (21083591621) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 101970 + ... + 229270.

It is an arithmetic number, because the mean of its divisors is an integer number (516400563).

Almost surely, 2^21083591620 is an apocalyptic number.

21083591620 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21083591620, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27885630402).

21083591620 is an abundant number, since it is smaller than the sum of its proper divisors (34687669184).

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

21083591620 is a wasteful number, since it uses less digits than its factorization.

21083591620 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 127350 (or 127328 counting only the distinct ones).

The product of its (nonzero) digits is 25920, while the sum is 37.

The spelling of 21083591620 in words is "twenty-one billion, eighty-three million, five hundred ninety-one thousand, six hundred twenty".