21214026137509 has 2 divisors, whose sum is σ = 21214026137510. Its totient is φ = 21214026137508.

The previous prime is 21214026137483. The next prime is 21214026137587. The reversal of 21214026137509 is 90573162041212.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20016872856484 + 1197153281025 = 4474022^2 + 1094145^2 .

It is a cyclic number.

It is not a de Polignac number, because 21214026137509 - 2⁹ = 21214026136997 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21214026137309) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10607013068754 + 10607013068755.

It is an arithmetic number, because the mean of its divisors is an integer number (10607013068755).

Almost surely, 2^{21214026137509} is an apocalyptic number.

It is an amenable number.

21214026137509 is a deficient number, since it is larger than the sum of its proper divisors (1).

21214026137509 is an equidigital number, since it uses as much as digits as its factorization.

21214026137509 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 181440, while the sum is 43.

The spelling of 21214026137509 in words is "twenty-one trillion, two hundred fourteen billion, twenty-six million, one hundred thirty-seven thousand, five hundred nine".