18436987 has 2 divisors, whose sum is σ = 18436988. Its totient is φ = 18436986.

The previous prime is 18436937. The next prime is 18437021. The reversal of 18436987 is 78963481.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 18436987 - 2¹⁵ = 18404219 is a prime.

It is a super-4 number, since 4×18436987⁴ (a number of 30 digits) contains 4444 as substring.

It is not a weakly prime, because it can be changed into another prime (18436937) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9218493 + 9218494.

It is an arithmetic number, because the mean of its divisors is an integer number (9218494).

Almost surely, 2^18436987 is an apocalyptic number.

18436987 is a deficient number, since it is larger than the sum of its proper divisors (1).

18436987 is an equidigital number, since it uses as much as digits as its factorization.

18436987 is an evil number, because the sum of its binary digits is even.

The product of its digits is 290304, while the sum is 46.

The square root of 18436987 is about 4293.8312728844. The cubic root of 18436987 is about 264.1780011302.

The spelling of 18436987 in words is "eighteen million, four hundred thirty-six thousand, nine hundred eighty-seven".