21588944257 has 2 divisors, whose sum is σ = 21588944258. Its totient is φ = 21588944256.

The previous prime is 21588944191. The next prime is 21588944261. The reversal of 21588944257 is 75244988512.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20310810256 + 1278134001 = 142516^2 + 35751^2 .

It is a cyclic number.

It is not a de Polignac number, because 21588944257 - 2¹⁵ = 21588911489 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21588944198 and 21588944207.

It is not a weakly prime, because it can be changed into another prime (21588914257) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10794472128 + 10794472129.

It is an arithmetic number, because the mean of its divisors is an integer number (10794472129).

Almost surely, 2^21588944257 is an apocalyptic number.

It is an amenable number.

21588944257 is a deficient number, since it is larger than the sum of its proper divisors (1).

21588944257 is an equidigital number, since it uses as much as digits as its factorization.

21588944257 is an evil number, because the sum of its binary digits is even.

The product of its digits is 6451200, while the sum is 55.

The spelling of 21588944257 in words is "twenty-one billion, five hundred eighty-eight million, nine hundred forty-four thousand, two hundred fifty-seven".