105591999 has 4 divisors (see below), whose sum is σ = 140789336. Its totient is φ = 70394664.

The previous prime is 105591989. The next prime is 105592007. The reversal of 105591999 is 999195501.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 999195501 = 3 ⋅333065167.

It is not a de Polignac number, because 105591999 - 2¹¹ = 105589951 is a prime.

It is a super-2 number, since 2×105591999² = 22299340505632002, 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 (105591989) 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, 17598664 + ... + 17598669.

It is an arithmetic number, because the mean of its divisors is an integer number (35197334).

Almost surely, 2^105591999 is an apocalyptic number.

105591999 is a deficient number, since it is larger than the sum of its proper divisors (35197337).

105591999 is an equidigital number, since it uses as much as digits as its factorization.

105591999 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 35197336.

The product of its (nonzero) digits is 164025, while the sum is 48.

The square root of 105591999 is about 10275.7967574296. The cubic root of 105591999 is about 472.6543623758.

The spelling of 105591999 in words is "one hundred five million, five hundred ninety-one thousand, nine hundred ninety-nine".