117661809 has 4 divisors (see below), whose sum is σ = 156882416. Its totient is φ = 78441204.

The previous prime is 117661793. The next prime is 117661823. The reversal of 117661809 is 908166711.

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 not a de Polignac number, because 117661809 - 2⁴ = 117661793 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (117661409) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 19610299 + ... + 19610304.

It is an arithmetic number, because the mean of its divisors is an integer number (39220604).

Almost surely, 2^117661809 is an apocalyptic number.

It is an amenable number.

117661809 is a deficient number, since it is larger than the sum of its proper divisors (39220607).

117661809 is an equidigital number, since it uses as much as digits as its factorization.

117661809 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 39220606.

The product of its (nonzero) digits is 18144, while the sum is 39.

The square root of 117661809 is about 10847.2028191603. The cubic root of 117661809 is about 490.0177822229.

The spelling of 117661809 in words is "one hundred seventeen million, six hundred sixty-one thousand, eight hundred nine".