21410321021 has 2 divisors, whose sum is σ = 21410321022. Its totient is φ = 21410321020.

The previous prime is 21410321017. The next prime is 21410321039. The reversal of 21410321021 is 12012301412.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18733396900 + 2676924121 = 136870^2 + 51739^2 .

It is a cyclic number.

It is not a de Polignac number, because 21410321021 - 2² = 21410321017 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21410321041) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10705160510 + 10705160511.

It is an arithmetic number, because the mean of its divisors is an integer number (10705160511).

Almost surely, 2^21410321021 is an apocalyptic number.

It is an amenable number.

21410321021 is a deficient number, since it is larger than the sum of its proper divisors (1).

21410321021 is an equidigital number, since it uses as much as digits as its factorization.

21410321021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 96, while the sum is 17.

Adding to 21410321021 its reverse (12012301412), we get a palindrome (33422622433).

The spelling of 21410321021 in words is "twenty-one billion, four hundred ten million, three hundred twenty-one thousand, twenty-one".