21945062317 has 2 divisors, whose sum is σ = 21945062318. Its totient is φ = 21945062316.

The previous prime is 21945062299. The next prime is 21945062327. The reversal of 21945062317 is 71326054912.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 15793954276 + 6151108041 = 125674^2 + 78429^2 .

It is a cyclic number.

It is not a de Polignac number, because 21945062317 - 2²³ = 21936673709 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21945062317.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21945062327) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10972531158 + 10972531159.

It is an arithmetic number, because the mean of its divisors is an integer number (10972531159).

Almost surely, 2^21945062317 is an apocalyptic number.

It is an amenable number.

21945062317 is a deficient number, since it is larger than the sum of its proper divisors (1).

21945062317 is an equidigital number, since it uses as much as digits as its factorization.

21945062317 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 90720, while the sum is 40.

The spelling of 21945062317 in words is "twenty-one billion, nine hundred forty-five million, sixty-two thousand, three hundred seventeen".