21351251301269 has 2 divisors, whose sum is σ = 21351251301270. Its totient is φ = 21351251301268.

The previous prime is 21351251301257. The next prime is 21351251301299. The reversal of 21351251301269 is 96210315215312.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 21239765430244 + 111485871025 = 4608662^2 + 333895^2 .

It is a cyclic number.

It is not a de Polignac number, because 21351251301269 - 2⁴⁴ = 3759065256853 is a prime.

It is a super-2 number, since 2×21351251301269² (a number of 27 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21351251301299) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10675625650634 + 10675625650635.

It is an arithmetic number, because the mean of its divisors is an integer number (10675625650635).

Almost surely, 2^{21351251301269} is an apocalyptic number.

It is an amenable number.

21351251301269 is a deficient number, since it is larger than the sum of its proper divisors (1).

21351251301269 is an equidigital number, since it uses as much as digits as its factorization.

21351251301269 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 97200, while the sum is 41.

The spelling of 21351251301269 in words is "twenty-one trillion, three hundred fifty-one billion, two hundred fifty-one million, three hundred one thousand, two hundred sixty-nine".