18007538 has 8 divisors (see below), whose sum is σ = 27046380. Its totient is φ = 8992080.

The previous prime is 18007537. The next prime is 18007547. The reversal of 18007538 is 83570081.

It can be written as a sum of positive squares in 2 ways, for example, as 18003049 + 4489 = 4243^2 + 67^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not an unprimeable number, because it can be changed into a prime (18007537) 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, 3773 + ... + 7088.

Almost surely, 2^18007538 is an apocalyptic number.

18007538 is a deficient number, since it is larger than the sum of its proper divisors (9038842).

18007538 is a wasteful number, since it uses less digits than its factorization.

18007538 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11692.

The product of its (nonzero) digits is 6720, while the sum is 32.

The square root of 18007538 is about 4243.5289559516. The cubic root of 18007538 is about 262.1107179238.

The spelling of 18007538 in words is "eighteen million, seven thousand, five hundred thirty-eight".