18401287 has 2 divisors, whose sum is σ = 18401288. Its totient is φ = 18401286.

The previous prime is 18401261. The next prime is 18401297. The reversal of 18401287 is 78210481.

It is a strong prime.

It is an emirp because it is prime and its reverse (78210481) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18401287 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18401297) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9200643 + 9200644.

It is an arithmetic number, because the mean of its divisors is an integer number (9200644).

Almost surely, 2^18401287 is an apocalyptic number.

18401287 is a deficient number, since it is larger than the sum of its proper divisors (1).

18401287 is an equidigital number, since it uses as much as digits as its factorization.

18401287 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3584, while the sum is 31.

The square root of 18401287 is about 4289.6721319933. The cubic root of 18401287 is about 264.0073794616.

The spelling of 18401287 in words is "eighteen million, four hundred one thousand, two hundred eighty-seven".