21672347756893 has 2 divisors, whose sum is σ = 21672347756894. Its totient is φ = 21672347756892.

The previous prime is 21672347756887. The next prime is 21672347756987. The reversal of 21672347756893 is 39865774327612.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 21324787987129 + 347559769764 = 4617877^2 + 589542^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21672347756893 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21672347751893) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10836173878446 + 10836173878447.

It is an arithmetic number, because the mean of its divisors is an integer number (10836173878447).

Almost surely, 2^{21672347756893} is an apocalyptic number.

It is an amenable number.

21672347756893 is a deficient number, since it is larger than the sum of its proper divisors (1).

21672347756893 is an equidigital number, since it uses as much as digits as its factorization.

21672347756893 is an evil number, because the sum of its binary digits is even.

The product of its digits is 640120320, while the sum is 70.

The spelling of 21672347756893 in words is "twenty-one trillion, six hundred seventy-two billion, three hundred forty-seven million, seven hundred fifty-six thousand, eight hundred ninety-three".