21522532021 has 2 divisors, whose sum is σ = 21522532022. Its totient is φ = 21522532020.

The previous prime is 21522531991. The next prime is 21522532051. The reversal of 21522532021 is 12023522512.

It is a balanced prime because it is at equal distance from previous prime (21522531991) and next prime (21522532051).

It can be written as a sum of positive squares in only one way, i.e., 16792531396 + 4730000625 = 129586^2 + 68775^2 .

It is a cyclic number.

It is not a de Polignac number, because 21522532021 - 2⁷ = 21522531893 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21522532051) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10761266010 + 10761266011.

It is an arithmetic number, because the mean of its divisors is an integer number (10761266011).

Almost surely, 2^21522532021 is an apocalyptic number.

It is an amenable number.

21522532021 is a deficient number, since it is larger than the sum of its proper divisors (1).

21522532021 is an equidigital number, since it uses as much as digits as its factorization.

21522532021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2400, while the sum is 25.

The spelling of 21522532021 in words is "twenty-one billion, five hundred twenty-two million, five hundred thirty-two thousand, twenty-one".