21116015797 has 2 divisors, whose sum is σ = 21116015798. Its totient is φ = 21116015796.

The previous prime is 21116015771. The next prime is 21116015801. The reversal of 21116015797 is 79751061112.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 14122707921 + 6993307876 = 118839^2 + 83626^2 .

It is a cyclic number.

It is not a de Polignac number, because 21116015797 - 2¹⁵ = 21115983029 is a prime.

It is a super-2 number, since 2×21116015797² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21116015497) 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, 10558007898 + 10558007899.

It is an arithmetic number, because the mean of its divisors is an integer number (10558007899).

Almost surely, 2^21116015797 is an apocalyptic number.

It is an amenable number.

21116015797 is a deficient number, since it is larger than the sum of its proper divisors (1).

21116015797 is an equidigital number, since it uses as much as digits as its factorization.

21116015797 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 26460, while the sum is 40.

The spelling of 21116015797 in words is "twenty-one billion, one hundred sixteen million, fifteen thousand, seven hundred ninety-seven".