21611766100511 has 2 divisors, whose sum is σ = 21611766100512. Its totient is φ = 21611766100510.

The previous prime is 21611766100481. The next prime is 21611766100517. The reversal of 21611766100511 is 11500166711612.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21611766100511 - 2³⁸ = 21336888193567 is a prime.

It is a super-2 number, since 2×21611766100511² (a number of 27 digits) contains 22 as substring.

It is a Sophie Germain prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21611766100517) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10805883050255 + 10805883050256.

It is an arithmetic number, because the mean of its divisors is an integer number (10805883050256).

Almost surely, 2^{21611766100511} is an apocalyptic number.

21611766100511 is a deficient number, since it is larger than the sum of its proper divisors (1).

21611766100511 is an equidigital number, since it uses as much as digits as its factorization.

21611766100511 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 15120, while the sum is 38.

The spelling of 21611766100511 in words is "twenty-one trillion, six hundred eleven billion, seven hundred sixty-six million, one hundred thousand, five hundred eleven".