21231635775841 has 2 divisors, whose sum is σ = 21231635775842. Its totient is φ = 21231635775840.

The previous prime is 21231635775769. The next prime is 21231635775913. The reversal of 21231635775841 is 14857753613212.

It is a happy number.

It is a balanced prime because it is at equal distance from previous prime (21231635775769) and next prime (21231635775913).

It can be written as a sum of positive squares in only one way, i.e., 12470503449600 + 8761132326241 = 3531360^2 + 2959921^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21231635775841 is a prime.

It is not a weakly prime, because it can be changed into another prime (21231635775341) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10615817887920 + 10615817887921.

It is an arithmetic number, because the mean of its divisors is an integer number (10615817887921).

Almost surely, 2^{21231635775841} is an apocalyptic number.

It is an amenable number.

21231635775841 is a deficient number, since it is larger than the sum of its proper divisors (1).

21231635775841 is an equidigital number, since it uses as much as digits as its factorization.

21231635775841 is an evil number, because the sum of its binary digits is even.

The product of its digits is 8467200, while the sum is 55.

The spelling of 21231635775841 in words is "twenty-one trillion, two hundred thirty-one billion, six hundred thirty-five million, seven hundred seventy-five thousand, eight hundred forty-one".