21985853191 has 2 divisors, whose sum is σ = 21985853192. Its totient is φ = 21985853190.

The previous prime is 21985853179. The next prime is 21985853231. The reversal of 21985853191 is 19135858912.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21985853191 - 2⁵ = 21985853159 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21985883191) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10992926595 + 10992926596.

It is an arithmetic number, because the mean of its divisors is an integer number (10992926596).

Almost surely, 2^21985853191 is an apocalyptic number.

21985853191 is a deficient number, since it is larger than the sum of its proper divisors (1).

21985853191 is an equidigital number, since it uses as much as digits as its factorization.

21985853191 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 777600, while the sum is 52.

The spelling of 21985853191 in words is "twenty-one billion, nine hundred eighty-five million, eight hundred fifty-three thousand, one hundred ninety-one".