21166311659 has 2 divisors, whose sum is σ = 21166311660. Its totient is φ = 21166311658.

The previous prime is 21166311653. The next prime is 21166311707. The reversal of 21166311659 is 95611366112.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21166311659 - 2⁴ = 21166311643 is a prime.

It is not a weakly prime, because it can be changed into another prime (21166311653) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10583155829 + 10583155830.

It is an arithmetic number, because the mean of its divisors is an integer number (10583155830).

Almost surely, 2^21166311659 is an apocalyptic number.

21166311659 is a deficient number, since it is larger than the sum of its proper divisors (1).

21166311659 is an equidigital number, since it uses as much as digits as its factorization.

21166311659 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 58320, while the sum is 41.

It can be divided in two parts, 211663 and 11659, that added together give a palindrome (223322).

The spelling of 21166311659 in words is "twenty-one billion, one hundred sixty-six million, three hundred eleven thousand, six hundred fifty-nine".