18998611 has 2 divisors, whose sum is σ = 18998612. Its totient is φ = 18998610.

The previous prime is 18998593. The next prime is 18998641. The reversal of 18998611 is 11689981.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 18998611 - 2¹¹ = 18996563 is a prime.

It is not a weakly prime, because it can be changed into another prime (18998641) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9499305 + 9499306.

It is an arithmetic number, because the mean of its divisors is an integer number (9499306).

Almost surely, 2^18998611 is an apocalyptic number.

18998611 is a deficient number, since it is larger than the sum of its proper divisors (1).

18998611 is an equidigital number, since it uses as much as digits as its factorization.

18998611 is an evil number, because the sum of its binary digits is even.

The product of its digits is 31104, while the sum is 43.

The square root of 18998611 is about 4358.7396114014. The cubic root of 18998611 is about 266.8336622402.

The spelling of 18998611 in words is "eighteen million, nine hundred ninety-eight thousand, six hundred eleven".