18897811 has 2 divisors, whose sum is σ = 18897812. Its totient is φ = 18897810.

The previous prime is 18897803. The next prime is 18897833. The reversal of 18897811 is 11879881.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 18897811 - 2³ = 18897803 is a prime.

It is not a weakly prime, because it can be changed into another prime (18897871) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9448905 + 9448906.

It is an arithmetic number, because the mean of its divisors is an integer number (9448906).

Almost surely, 2^18897811 is an apocalyptic number.

18897811 is a deficient number, since it is larger than the sum of its proper divisors (1).

18897811 is an equidigital number, since it uses as much as digits as its factorization.

18897811 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 32256, while the sum is 43.

The square root of 18897811 is about 4347.1612576485. The cubic root of 18897811 is about 266.3609164122.

The spelling of 18897811 in words is "eighteen million, eight hundred ninety-seven thousand, eight hundred eleven".