105789991 has 4 divisors (see below), whose sum is σ = 106423632. Its totient is φ = 105156352.

The previous prime is 105789973. The next prime is 105790001. The reversal of 105789991 is 199987501.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 105789991 - 2⁷ = 105789863 is a prime.

It is a super-2 number, since 2×105789991² = 22383044391560162, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (105789911) 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, 316570 + ... + 316903.

It is an arithmetic number, because the mean of its divisors is an integer number (26605908).

Almost surely, 2^105789991 is an apocalyptic number.

105789991 is a deficient number, since it is larger than the sum of its proper divisors (633641).

105789991 is an equidigital number, since it uses as much as digits as its factorization.

105789991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 633640.

The product of its (nonzero) digits is 204120, while the sum is 49.

The square root of 105789991 is about 10285.4261457657. The cubic root of 105789991 is about 472.9495973481.

The spelling of 105789991 in words is "one hundred five million, seven hundred eighty-nine thousand, nine hundred ninety-one".