18871903 has 2 divisors, whose sum is σ = 18871904. Its totient is φ = 18871902.

The previous prime is 18871889. The next prime is 18871907. The reversal of 18871903 is 30917881.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18871903 is a prime.

It is a super-2 number, since 2×18871903² = 712297445682818, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18871907) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9435951 + 9435952.

It is an arithmetic number, because the mean of its divisors is an integer number (9435952).

Almost surely, 2^18871903 is an apocalyptic number.

18871903 is a deficient number, since it is larger than the sum of its proper divisors (1).

18871903 is an equidigital number, since it uses as much as digits as its factorization.

18871903 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 12096, while the sum is 37.

The square root of 18871903 is about 4344.1803599759. The cubic root of 18871903 is about 266.2391380288.

The spelling of 18871903 in words is "eighteen million, eight hundred seventy-one thousand, nine hundred three".