18250009 has 4 divisors (see below), whose sum is σ = 18273060. Its totient is φ = 18226960.

The previous prime is 18249997. The next prime is 18250021. The reversal of 18250009 is 90005281.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 90005281 = 127 ⋅708703.

It is an interprime number because it is at equal distance from previous prime (18249997) and next prime (18250021).

It can be written as a sum of positive squares in 2 ways, for example, as 4963984 + 13286025 = 2228^2 + 3645^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18250009 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18250039) 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, 10294 + ... + 11935.

It is an arithmetic number, because the mean of its divisors is an integer number (4568265).

Almost surely, 2^18250009 is an apocalyptic number.

It is an amenable number.

18250009 is a deficient number, since it is larger than the sum of its proper divisors (23051).

18250009 is an equidigital number, since it uses as much as digits as its factorization.

18250009 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23050.

The product of its (nonzero) digits is 720, while the sum is 25.

The square root of 18250009 is about 4272.0029260290. The cubic root of 18250009 is about 263.2819146878.

Subtracting from 18250009 its sum of digits (25), we obtain a square (18249984 = 4272²).

The spelling of 18250009 in words is "eighteen million, two hundred fifty thousand, nine".