21867940811 has 2 divisors, whose sum is σ = 21867940812. Its totient is φ = 21867940810.

The previous prime is 21867940789. The next prime is 21867940819. The reversal of 21867940811 is 11804976812.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21867940811 - 2³⁰ = 20794198987 is a prime.

It is not a weakly prime, because it can be changed into another prime (21867940819) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10933970405 + 10933970406.

It is an arithmetic number, because the mean of its divisors is an integer number (10933970406).

Almost surely, 2^21867940811 is an apocalyptic number.

21867940811 is a deficient number, since it is larger than the sum of its proper divisors (1).

21867940811 is an equidigital number, since it uses as much as digits as its factorization.

21867940811 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 193536, while the sum is 47.

The spelling of 21867940811 in words is "twenty-one billion, eight hundred sixty-seven million, nine hundred forty thousand, eight hundred eleven".