18637985 has 8 divisors (see below), whose sum is σ = 22911336. Its totient is φ = 14546560.

The previous prime is 18637979. The next prime is 18637987. The reversal of 18637985 is 58973681.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 379456 + 18258529 = 616^2 + 4273^2 .

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

It is not a de Polignac number, because 18637985 - 2⁶ = 18637921 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (18637987) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 45254 + ... + 45663.

It is an arithmetic number, because the mean of its divisors is an integer number (2863917).

Almost surely, 2^18637985 is an apocalyptic number.

It is an amenable number.

18637985 is a deficient number, since it is larger than the sum of its proper divisors (4273351).

18637985 is an equidigital number, since it uses as much as digits as its factorization.

18637985 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 90963.

The product of its digits is 362880, while the sum is 47.

The square root of 18637985 is about 4317.1732649964. The cubic root of 18637985 is about 265.1345466042.

The spelling of 18637985 in words is "eighteen million, six hundred thirty-seven thousand, nine hundred eighty-five".