21035520013 has 2 divisors, whose sum is σ = 21035520014. Its totient is φ = 21035520012.

The previous prime is 21035519987. The next prime is 21035520017. The reversal of 21035520013 is 31002553012.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 11210150884 + 9825369129 = 105878^2 + 99123^2 .

It is a cyclic number.

It is not a de Polignac number, because 21035520013 - 2²⁵ = 21001965581 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21035520017) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10517760006 + 10517760007.

It is an arithmetic number, because the mean of its divisors is an integer number (10517760007).

Almost surely, 2^21035520013 is an apocalyptic number.

It is an amenable number.

21035520013 is a deficient number, since it is larger than the sum of its proper divisors (1).

21035520013 is an equidigital number, since it uses as much as digits as its factorization.

21035520013 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 900, while the sum is 22.

The spelling of 21035520013 in words is "twenty-one billion, thirty-five million, five hundred twenty thousand, thirteen".