18884891 has 2 divisors, whose sum is σ = 18884892. Its totient is φ = 18884890.

The previous prime is 18884851. The next prime is 18884927. The reversal of 18884891 is 19848881.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18884891 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (18884851) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9442445 + 9442446.

It is an arithmetic number, because the mean of its divisors is an integer number (9442446).

Almost surely, 2^18884891 is an apocalyptic number.

18884891 is a deficient number, since it is larger than the sum of its proper divisors (1).

18884891 is an equidigital number, since it uses as much as digits as its factorization.

18884891 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 147456, while the sum is 47.

The square root of 18884891 is about 4345.6749763414. The cubic root of 18884891 is about 266.3002009568.

The spelling of 18884891 in words is "eighteen million, eight hundred eighty-four thousand, eight hundred ninety-one".