21100119991 has 2 divisors, whose sum is σ = 21100119992. Its totient is φ = 21100119990.

The previous prime is 21100119967. The next prime is 21100120001. The reversal of 21100119991 is 19991100112.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21100119991 - 2⁷ = 21100119863 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21100159991) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10550059995 + 10550059996.

It is an arithmetic number, because the mean of its divisors is an integer number (10550059996).

Almost surely, 2^21100119991 is an apocalyptic number.

21100119991 is a deficient number, since it is larger than the sum of its proper divisors (1).

21100119991 is an equidigital number, since it uses as much as digits as its factorization.

21100119991 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1458, while the sum is 34.

The spelling of 21100119991 in words is "twenty-one billion, one hundred million, one hundred nineteen thousand, nine hundred ninety-one".