21023264161 has 2 divisors, whose sum is σ = 21023264162. Its totient is φ = 21023264160.

The previous prime is 21023264113. The next prime is 21023264177. The reversal of 21023264161 is 16146232012.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 11530464400 + 9492799761 = 107380^2 + 97431^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21023264161 is a prime.

It is not a weakly prime, because it can be changed into another prime (21023264261) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10511632080 + 10511632081.

It is an arithmetic number, because the mean of its divisors is an integer number (10511632081).

Almost surely, 2^21023264161 is an apocalyptic number.

It is an amenable number.

21023264161 is a deficient number, since it is larger than the sum of its proper divisors (1).

21023264161 is an equidigital number, since it uses as much as digits as its factorization.

21023264161 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3456, while the sum is 28.

Adding to 21023264161 its reverse (16146232012), we get a palindrome (37169496173).

The spelling of 21023264161 in words is "twenty-one billion, twenty-three million, two hundred sixty-four thousand, one hundred sixty-one".