21687193711 has 2 divisors, whose sum is σ = 21687193712. Its totient is φ = 21687193710.

The previous prime is 21687193687. The next prime is 21687193751. The reversal of 21687193711 is 11739178612.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21687193711 - 2¹¹ = 21687191663 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21687193751) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10843596855 + 10843596856.

It is an arithmetic number, because the mean of its divisors is an integer number (10843596856).

Almost surely, 2^21687193711 is an apocalyptic number.

21687193711 is a deficient number, since it is larger than the sum of its proper divisors (1).

21687193711 is an equidigital number, since it uses as much as digits as its factorization.

21687193711 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 127008, while the sum is 46.

The spelling of 21687193711 in words is "twenty-one billion, six hundred eighty-seven million, one hundred ninety-three thousand, seven hundred eleven".