18156241 has 4 divisors (see below), whose sum is σ = 18542592. Its totient is φ = 17769892.

The previous prime is 18156227. The next prime is 18156251. The reversal of 18156241 is 14265181.

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 18156241 - 2⁵ = 18156209 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18156211) 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, 193105 + ... + 193198.

It is an arithmetic number, because the mean of its divisors is an integer number (4635648).

Almost surely, 2^18156241 is an apocalyptic number.

It is an amenable number.

18156241 is a deficient number, since it is larger than the sum of its proper divisors (386351).

18156241 is an equidigital number, since it uses as much as digits as its factorization.

18156241 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 386350.

The product of its digits is 1920, while the sum is 28.

The square root of 18156241 is about 4261.0140811783. The cubic root of 18156241 is about 262.8302286867.

The spelling of 18156241 in words is "eighteen million, one hundred fifty-six thousand, two hundred forty-one".