18445387 has 4 divisors (see below), whose sum is σ = 18479656. Its totient is φ = 18411120.

The previous prime is 18445381. The next prime is 18445393. The reversal of 18445387 is 78354481.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 78354481 = 149 ⋅525869.

It is an interprime number because it is at equal distance from previous prime (18445381) and next prime (18445393).

It is a cyclic number.

It is not a de Polignac number, because 18445387 - 2¹¹ = 18443339 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18445381) 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, 16314 + ... + 17407.

It is an arithmetic number, because the mean of its divisors is an integer number (4619914).

Almost surely, 2^18445387 is an apocalyptic number.

18445387 is a deficient number, since it is larger than the sum of its proper divisors (34269).

18445387 is an equidigital number, since it uses as much as digits as its factorization.

18445387 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 34268.

The product of its digits is 107520, while the sum is 40.

The square root of 18445387 is about 4294.8093089216. The cubic root of 18445387 is about 264.2181153905.

The spelling of 18445387 in words is "eighteen million, four hundred forty-five thousand, three hundred eighty-seven".