18195959 has 4 divisors (see below), whose sum is σ = 18238416. Its totient is φ = 18153504.

The previous prime is 18195937. The next prime is 18196019. The reversal of 18195959 is 95959181.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18195959 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (14195959) 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, 20579 + ... + 21444.

It is an arithmetic number, because the mean of its divisors is an integer number (4559604).

Almost surely, 2^18195959 is an apocalyptic number.

18195959 is a deficient number, since it is larger than the sum of its proper divisors (42457).

18195959 is an equidigital number, since it uses as much as digits as its factorization.

18195959 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 42456.

The product of its digits is 145800, while the sum is 47.

The square root of 18195959 is about 4265.6721627429. The cubic root of 18195959 is about 263.0217420473.

The spelling of 18195959 in words is "eighteen million, one hundred ninety-five thousand, nine hundred fifty-nine".