18220287 has 8 divisors (see below), whose sum is σ = 24752304. Its totient is φ = 11917568.

The previous prime is 18220283. The next prime is 18220291. The reversal of 18220287 is 78202281.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (18220283) and next prime (18220291).

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 18220287 - 2² = 18220283 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18220283) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 57138 + ... + 57455.

It is an arithmetic number, because the mean of its divisors is an integer number (3094038).

Almost surely, 2^18220287 is an apocalyptic number.

18220287 is a deficient number, since it is larger than the sum of its proper divisors (6532017).

18220287 is a wasteful number, since it uses less digits than its factorization.

18220287 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 114649.

The product of its (nonzero) digits is 3584, while the sum is 30.

The square root of 18220287 is about 4268.5228124024. The cubic root of 18220287 is about 263.1389098816.

The spelling of 18220287 in words is "eighteen million, two hundred twenty thousand, two hundred eighty-seven".