105840209 has 4 divisors (see below), whose sum is σ = 106021104. Its totient is φ = 105659316.

The previous prime is 105840191. The next prime is 105840233. The reversal of 105840209 is 902048501.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 105840209 - 2¹² = 105836113 is a prime.

It is a super-2 number, since 2×105840209² = 22404299682327362, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (105840109) 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, 89567 + ... + 90740.

It is an arithmetic number, because the mean of its divisors is an integer number (26505276).

Almost surely, 2^105840209 is an apocalyptic number.

It is an amenable number.

105840209 is a deficient number, since it is larger than the sum of its proper divisors (180895).

105840209 is an equidigital number, since it uses as much as digits as its factorization.

105840209 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 180894.

The product of its (nonzero) digits is 2880, while the sum is 29.

The square root of 105840209 is about 10287.8670772906. The cubic root of 105840209 is about 473.0244211430.

The spelling of 105840209 in words is "one hundred five million, eight hundred forty thousand, two hundred nine".