21351435013 has 2 divisors, whose sum is σ = 21351435014. Its totient is φ = 21351435012.

The previous prime is 21351434981. The next prime is 21351435019. The reversal of 21351435013 is 31053415312.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 15765815844 + 5585619169 = 125562^2 + 74737^2 .

It is a cyclic number.

It is not a de Polignac number, because 21351435013 - 2⁵ = 21351434981 is a prime.

It is a super-2 number, since 2×21351435013² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21351435019) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10675717506 + 10675717507.

It is an arithmetic number, because the mean of its divisors is an integer number (10675717507).

Almost surely, 2^21351435013 is an apocalyptic number.

It is an amenable number.

21351435013 is a deficient number, since it is larger than the sum of its proper divisors (1).

21351435013 is an equidigital number, since it uses as much as digits as its factorization.

21351435013 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 5400, while the sum is 28.

The spelling of 21351435013 in words is "twenty-one billion, three hundred fifty-one million, four hundred thirty-five thousand, thirteen".