18008437 has 4 divisors (see below), whose sum is σ = 18022240. Its totient is φ = 17994636.

The previous prime is 18008413. The next prime is 18008467. The reversal of 18008437 is 73480081.

It is a happy number.

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, and also an emirpimes, since its reverse is a distinct semiprime: 73480081 = 6959 ⋅10559.

It is a cyclic number.

It is not a de Polignac number, because 18008437 - 2¹¹ = 18006389 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 18008399 and 18008408.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18008467) 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, 4713 + ... + 7630.

It is an arithmetic number, because the mean of its divisors is an integer number (4505560).

Almost surely, 2^18008437 is an apocalyptic number.

It is an amenable number.

18008437 is a deficient number, since it is larger than the sum of its proper divisors (13803).

18008437 is a wasteful number, since it uses less digits than its factorization.

18008437 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13802.

The product of its (nonzero) digits is 5376, while the sum is 31.

The square root of 18008437 is about 4243.6348806183. The cubic root of 18008437 is about 262.1150796827.

The spelling of 18008437 in words is "eighteen million, eight thousand, four hundred thirty-seven".