18616987 has 2 divisors, whose sum is σ = 18616988. Its totient is φ = 18616986.

The previous prime is 18616943. The next prime is 18616999. The reversal of 18616987 is 78961681.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 18616987 - 2¹⁵ = 18584219 is a prime.

It is a plaindrome in base 14.

It is not a weakly prime, because it can be changed into another prime (18616907) 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, 9308493 + 9308494.

It is an arithmetic number, because the mean of its divisors is an integer number (9308494).

Almost surely, 2^18616987 is an apocalyptic number.

18616987 is a deficient number, since it is larger than the sum of its proper divisors (1).

18616987 is an equidigital number, since it uses as much as digits as its factorization.

18616987 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 145152, while the sum is 46.

The square root of 18616987 is about 4314.7406642810. The cubic root of 18616987 is about 265.0349402132.

The spelling of 18616987 in words is "eighteen million, six hundred sixteen thousand, nine hundred eighty-seven".