21711019879 has 2 divisors, whose sum is σ = 21711019880. Its totient is φ = 21711019878.

The previous prime is 21711019861. The next prime is 21711019909. The reversal of 21711019879 is 97891011712.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21711019879 - 2⁷ = 21711019751 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21711019819) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10855509939 + 10855509940.

It is an arithmetic number, because the mean of its divisors is an integer number (10855509940).

Almost surely, 2^21711019879 is an apocalyptic number.

21711019879 is a deficient number, since it is larger than the sum of its proper divisors (1).

21711019879 is an equidigital number, since it uses as much as digits as its factorization.

21711019879 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 63504, while the sum is 46.

The spelling of 21711019879 in words is "twenty-one billion, seven hundred eleven million, nineteen thousand, eight hundred seventy-nine".