105991591 has 2 divisors, whose sum is σ = 105991592. Its totient is φ = 105991590.

The previous prime is 105991577. The next prime is 105991619. The reversal of 105991591 is 195199501.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 105991591 - 2⁷ = 105991463 is a prime.

It is a super-2 number, since 2×105991591² = 22468434725422562, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (105991541) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 52995795 + 52995796.

It is an arithmetic number, because the mean of its divisors is an integer number (52995796).

Almost surely, 2^105991591 is an apocalyptic number.

105991591 is a deficient number, since it is larger than the sum of its proper divisors (1).

105991591 is an equidigital number, since it uses as much as digits as its factorization.

105991591 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 18225, while the sum is 40.

The square root of 105991591 is about 10295.2217557467. The cubic root of 105991591 is about 473.2498341216.

The spelling of 105991591 in words is "one hundred five million, nine hundred ninety-one thousand, five hundred ninety-one".