21163836008857 has 2 divisors, whose sum is σ = 21163836008858. Its totient is φ = 21163836008856.

The previous prime is 21163836008801. The next prime is 21163836008869. The reversal of 21163836008857 is 75880063836112.

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., 12139795976841 + 9024040032016 = 3484221^2 + 3004004^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21163836008857 is a prime.

It is not a weakly prime, because it can be changed into another prime (21163836005857) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10581918004428 + 10581918004429.

It is an arithmetic number, because the mean of its divisors is an integer number (10581918004429).

Almost surely, 2^{21163836008857} is an apocalyptic number.

It is an amenable number.

21163836008857 is a deficient number, since it is larger than the sum of its proper divisors (1).

21163836008857 is an equidigital number, since it uses as much as digits as its factorization.

21163836008857 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 11612160, while the sum is 58.

The spelling of 21163836008857 in words is "twenty-one trillion, one hundred sixty-three billion, eight hundred thirty-six million, eight thousand, eight hundred fifty-seven".