21100233321991 has 2 divisors, whose sum is σ = 21100233321992. Its totient is φ = 21100233321990.

The previous prime is 21100233321977. The next prime is 21100233322037. The reversal of 21100233321991 is 19912333200112.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21100233321991 - 2¹¹ = 21100233319943 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21100233321991.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21100233321911) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10550116660995 + 10550116660996.

It is an arithmetic number, because the mean of its divisors is an integer number (10550116660996).

Almost surely, 2^{21100233321991} is an apocalyptic number.

21100233321991 is a deficient number, since it is larger than the sum of its proper divisors (1).

21100233321991 is an equidigital number, since it uses as much as digits as its factorization.

21100233321991 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 17496, while the sum is 37.

The spelling of 21100233321991 in words is "twenty-one trillion, one hundred billion, two hundred thirty-three million, three hundred twenty-one thousand, nine hundred ninety-one".