18511859 has 2 divisors, whose sum is σ = 18511860. Its totient is φ = 18511858.

The previous prime is 18511841. The next prime is 18511903. The reversal of 18511859 is 95811581.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18511859 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (18511819) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9255929 + 9255930.

It is an arithmetic number, because the mean of its divisors is an integer number (9255930).

Almost surely, 2^18511859 is an apocalyptic number.

18511859 is a deficient number, since it is larger than the sum of its proper divisors (1).

18511859 is an equidigital number, since it uses as much as digits as its factorization.

18511859 is an evil number, because the sum of its binary digits is even.

The product of its digits is 14400, while the sum is 38.

The square root of 18511859 is about 4302.5409934131. The cubic root of 18511859 is about 264.5351242122.

The spelling of 18511859 in words is "eighteen million, five hundred eleven thousand, eight hundred fifty-nine".