21112011779 has 2 divisors, whose sum is σ = 21112011780. Its totient is φ = 21112011778.

The previous prime is 21112011761. The next prime is 21112011853. The reversal of 21112011779 is 97711021112.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21112011779 is a prime.

It is not a weakly prime, because it can be changed into another prime (21112014779) 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, 10556005889 + 10556005890.

It is an arithmetic number, because the mean of its divisors is an integer number (10556005890).

Almost surely, 2^21112011779 is an apocalyptic number.

21112011779 is a deficient number, since it is larger than the sum of its proper divisors (1).

21112011779 is an equidigital number, since it uses as much as digits as its factorization.

21112011779 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1764, while the sum is 32.

The spelling of 21112011779 in words is "twenty-one billion, one hundred twelve million, eleven thousand, seven hundred seventy-nine".