18712387 has 2 divisors, whose sum is σ = 18712388. Its totient is φ = 18712386.

The previous prime is 18712361. The next prime is 18712391. The reversal of 18712387 is 78321781.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 18712387 - 2⁷ = 18712259 is a prime.

It is not a weakly prime, because it can be changed into another prime (18712327) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9356193 + 9356194.

It is an arithmetic number, because the mean of its divisors is an integer number (9356194).

Almost surely, 2^18712387 is an apocalyptic number.

18712387 is a deficient number, since it is larger than the sum of its proper divisors (1).

18712387 is an equidigital number, since it uses as much as digits as its factorization.

18712387 is an evil number, because the sum of its binary digits is even.

The product of its digits is 18816, while the sum is 37.

The square root of 18712387 is about 4325.7816634685. The cubic root of 18712387 is about 265.4868799250.

The spelling of 18712387 in words is "eighteen million, seven hundred twelve thousand, three hundred eighty-seven".