18117901 has 4 divisors (see below), whose sum is σ = 18607612. Its totient is φ = 17628192.

The previous prime is 18117899. The next prime is 18117907. The reversal of 18117901 is 10971181.

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

It can be written as a sum of positive squares in 2 ways, for example, as 6734025 + 11383876 = 2595^2 + 3374^2 .

It is a cyclic number.

It is not a de Polignac number, because 18117901 - 2¹ = 18117899 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 18117901.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18117907) 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, 244800 + ... + 244873.

It is an arithmetic number, because the mean of its divisors is an integer number (4651903).

Almost surely, 2^18117901 is an apocalyptic number.

It is an amenable number.

18117901 is a deficient number, since it is larger than the sum of its proper divisors (489711).

18117901 is an equidigital number, since it uses as much as digits as its factorization.

18117901 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 489710.

The product of its (nonzero) digits is 504, while the sum is 28.

The square root of 18117901 is about 4256.5127745609. The cubic root of 18117901 is about 262.6450946909.

The spelling of 18117901 in words is "eighteen million, one hundred seventeen thousand, nine hundred one".