21973547635213 has 2 divisors, whose sum is σ = 21973547635214. Its totient is φ = 21973547635212.

The previous prime is 21973547635157. The next prime is 21973547635243. The reversal of 21973547635213 is 31253674537912.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 14254113313444 + 7719434321769 = 3775462^2 + 2778387^2 .

It is a cyclic number.

It is not a de Polignac number, because 21973547635213 - 2¹⁷ = 21973547504141 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21973547635243) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10986773817606 + 10986773817607.

It is an arithmetic number, because the mean of its divisors is an integer number (10986773817607).

Almost surely, 2^{21973547635213} is an apocalyptic number.

It is an amenable number.

21973547635213 is a deficient number, since it is larger than the sum of its proper divisors (1).

21973547635213 is an equidigital number, since it uses as much as digits as its factorization.

21973547635213 is an evil number, because the sum of its binary digits is even.

The product of its digits is 28576800, while the sum is 58.

The spelling of 21973547635213 in words is "twenty-one trillion, nine hundred seventy-three billion, five hundred forty-seven million, six hundred thirty-five thousand, two hundred thirteen".