20051985 has 8 divisors (see below), whose sum is σ = 32083200. Its totient is φ = 10694384.

The previous prime is 20051971. The next prime is 20051987. The reversal of 20051985 is 58915002.

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 20051985 - 2⁵ = 20051953 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20051987) 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 in 7 ways as a sum of consecutive naturals, for example, 668385 + ... + 668414.

It is an arithmetic number, because the mean of its divisors is an integer number (4010400).

Almost surely, 2^20051985 is an apocalyptic number.

It is an amenable number.

20051985 is a deficient number, since it is larger than the sum of its proper divisors (12031215).

20051985 is a wasteful number, since it uses less digits than its factorization.

20051985 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1336807.

The product of its (nonzero) digits is 3600, while the sum is 30.

The square root of 20051985 is about 4477.9442828155. The cubic root of 20051985 is about 271.6767398542.

Adding to 20051985 its reverse (58915002), we get a palindrome (78966987).

The spelling of 20051985 in words is "twenty million, fifty-one thousand, nine hundred eighty-five".