21120982621 has 2 divisors, whose sum is σ = 21120982622. Its totient is φ = 21120982620.

The previous prime is 21120982601. The next prime is 21120982657. The reversal of 21120982621 is 12628902112.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 17374930596 + 3746052025 = 131814^2 + 61205^2 .

It is a cyclic number.

It is not a de Polignac number, because 21120982621 - 2¹³ = 21120974429 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21120982601) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10560491310 + 10560491311.

It is an arithmetic number, because the mean of its divisors is an integer number (10560491311).

Almost surely, 2^21120982621 is an apocalyptic number.

It is an amenable number.

21120982621 is a deficient number, since it is larger than the sum of its proper divisors (1).

21120982621 is an equidigital number, since it uses as much as digits as its factorization.

21120982621 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 6912, while the sum is 34.

The spelling of 21120982621 in words is "twenty-one billion, one hundred twenty million, nine hundred eighty-two thousand, six hundred twenty-one".