105890991 has 4 divisors (see below), whose sum is σ = 141187992. Its totient is φ = 70593992.

The previous prime is 105890921. The next prime is 105891007. The reversal of 105890991 is 199098501.

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 105890991 - 2¹¹ = 105888943 is a prime.

It is a super-2 number, since 2×105890991² = 22425803949924162, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (105890921) 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, 17648496 + ... + 17648501.

It is an arithmetic number, because the mean of its divisors is an integer number (35296998).

Almost surely, 2^105890991 is an apocalyptic number.

105890991 is a deficient number, since it is larger than the sum of its proper divisors (35297001).

105890991 is an equidigital number, since it uses as much as digits as its factorization.

105890991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 35297000.

The product of its (nonzero) digits is 29160, while the sum is 42.

The square root of 105890991 is about 10290.3348342024. The cubic root of 105890991 is about 473.1000612223.

The spelling of 105890991 in words is "one hundred five million, eight hundred ninety thousand, nine hundred ninety-one".