113821891 has 2 divisors, whose sum is σ = 113821892. Its totient is φ = 113821890.

The previous prime is 113821889. The next prime is 113821909. The reversal of 113821891 is 198128311.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 113821891 - 2¹ = 113821889 is a prime.

Together with 113821889, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (113821861) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 56910945 + 56910946.

It is an arithmetic number, because the mean of its divisors is an integer number (56910946).

Almost surely, 2^113821891 is an apocalyptic number.

113821891 is the 6748-th centered pentagonal number.

113821891 is a deficient number, since it is larger than the sum of its proper divisors (1).

113821891 is an equidigital number, since it uses as much as digits as its factorization.

113821891 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3456, while the sum is 34.

The square root of 113821891 is about 10668.7342735678. The cubic root of 113821891 is about 484.6281075837.

The spelling of 113821891 in words is "one hundred thirteen million, eight hundred twenty-one thousand, eight hundred ninety-one".