20018985 has 16 divisors (see below), whose sum is σ = 36606336. Its totient is φ = 9151488.

The previous prime is 20018981. The next prime is 20019023. The reversal of 20018985 is 58981002.

It is a happy number.

It is not a de Polignac number, because 20018985 - 2² = 20018981 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20018981) 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 15 ways as a sum of consecutive naturals, for example, 95224 + ... + 95433.

It is an arithmetic number, because the mean of its divisors is an integer number (2287896).

Almost surely, 2^20018985 is an apocalyptic number.

It is an amenable number.

20018985 is a deficient number, since it is larger than the sum of its proper divisors (16587351).

20018985 is a wasteful number, since it uses less digits than its factorization.

20018985 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 190672.

The product of its (nonzero) digits is 5760, while the sum is 33.

The square root of 20018985 is about 4474.2580390496. The cubic root of 20018985 is about 271.5276231946.

Adding to 20018985 its reverse (58981002), we get a palindrome (78999987).

The spelling of 20018985 in words is "twenty million, eighteen thousand, nine hundred eighty-five".