109919891 has 4 divisors (see below), whose sum is σ = 111783000. Its totient is φ = 108056784.

The previous prime is 109919881. The next prime is 109919899. The reversal of 109919891 is 198919901.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-109919891 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (109919899) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 931466 + ... + 931583.

It is an arithmetic number, because the mean of its divisors is an integer number (27945750).

Almost surely, 2^109919891 is an apocalyptic number.

109919891 is a deficient number, since it is larger than the sum of its proper divisors (1863109).

109919891 is an equidigital number, since it uses as much as digits as its factorization.

109919891 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1863108.

The product of its (nonzero) digits is 52488, while the sum is 47.

The square root of 109919891 is about 10484.2687394019. The cubic root of 109919891 is about 479.0256435642.

The spelling of 109919891 in words is "one hundred nine million, nine hundred nineteen thousand, eight hundred ninety-one".