21883853653621 has 2 divisors, whose sum is σ = 21883853653622. Its totient is φ = 21883853653620.

The previous prime is 21883853653601. The next prime is 21883853653631. The reversal of 21883853653621 is 12635635838812.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20914514951121 + 969338702500 = 4573239^2 + 984550^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21883853653621 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21883853653621.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21883853653601) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10941926826810 + 10941926826811.

It is an arithmetic number, because the mean of its divisors is an integer number (10941926826811).

Almost surely, 2^{21883853653621} is an apocalyptic number.

It is an amenable number.

21883853653621 is a deficient number, since it is larger than the sum of its proper divisors (1).

21883853653621 is an equidigital number, since it uses as much as digits as its factorization.

21883853653621 is an evil number, because the sum of its binary digits is even.

The product of its digits is 49766400, while the sum is 61.

The spelling of 21883853653621 in words is "twenty-one trillion, eight hundred eighty-three billion, eight hundred fifty-three million, six hundred fifty-three thousand, six hundred twenty-one".