18002251 has 4 divisors (see below), whose sum is σ = 18420952. Its totient is φ = 17583552.

The previous prime is 18002249. The next prime is 18002273. The reversal of 18002251 is 15220081.

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

It is a cyclic number.

It is not a de Polignac number, because 18002251 - 2¹ = 18002249 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18002051) 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, 209286 + ... + 209371.

It is an arithmetic number, because the mean of its divisors is an integer number (4605238).

Almost surely, 2^18002251 is an apocalyptic number.

18002251 is a deficient number, since it is larger than the sum of its proper divisors (418701).

18002251 is an equidigital number, since it uses as much as digits as its factorization.

18002251 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 418700.

The product of its (nonzero) digits is 160, while the sum is 19.

The square root of 18002251 is about 4242.9059617201. The cubic root of 18002251 is about 262.0850635746.

The spelling of 18002251 in words is "eighteen million, two thousand, two hundred fifty-one".