21430525334021 has 2 divisors, whose sum is σ = 21430525334022. Its totient is φ = 21430525334020.

The previous prime is 21430525334017. The next prime is 21430525334047. The reversal of 21430525334021 is 12043352503412.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 21242420102500 + 188105231521 = 4608950^2 + 433711^2 .

It is a cyclic number.

It is not a de Polignac number, because 21430525334021 - 2² = 21430525334017 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21430525334011) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10715262667010 + 10715262667011.

It is an arithmetic number, because the mean of its divisors is an integer number (10715262667011).

Almost surely, 2^{21430525334021} is an apocalyptic number.

It is an amenable number.

21430525334021 is a deficient number, since it is larger than the sum of its proper divisors (1).

21430525334021 is an equidigital number, since it uses as much as digits as its factorization.

21430525334021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 86400, while the sum is 35.

Adding to 21430525334021 its reverse (12043352503412), we get a palindrome (33473877837433).

The spelling of 21430525334021 in words is "twenty-one trillion, four hundred thirty billion, five hundred twenty-five million, three hundred thirty-four thousand, twenty-one".