118781809 has 4 divisors (see below), whose sum is σ = 120795120. Its totient is φ = 116768500.

The previous prime is 118781783. The next prime is 118781813. The reversal of 118781809 is 908187811.

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 118781809 - 2¹⁷ = 118650737 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (118781899) 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, 1006567 + ... + 1006684.

It is an arithmetic number, because the mean of its divisors is an integer number (30198780).

Almost surely, 2^118781809 is an apocalyptic number.

It is an amenable number.

118781809 is a deficient number, since it is larger than the sum of its proper divisors (2013311).

118781809 is an equidigital number, since it uses as much as digits as its factorization.

118781809 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2013310.

The product of its (nonzero) digits is 32256, while the sum is 43.

The square root of 118781809 is about 10898.7067581434. The cubic root of 118781809 is about 491.5676697105.

The spelling of 118781809 in words is "one hundred eighteen million, seven hundred eighty-one thousand, eight hundred nine".