20499985 has 16 divisors (see below), whose sum is σ = 26985600. Its totient is φ = 14826240.

The previous prime is 20499971. The next prime is 20500019. The reversal of 20499985 is 58999402.

It is not a de Polignac number, because 20499985 - 2⁵ = 20499953 is a prime.

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 10009 + ... + 11881.

It is an arithmetic number, because the mean of its divisors is an integer number (1686600).

Almost surely, 2^20499985 is an apocalyptic number.

It is an amenable number.

20499985 is a deficient number, since it is larger than the sum of its proper divisors (6485615).

20499985 is a wasteful number, since it uses less digits than its factorization.

20499985 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2088.

The product of its (nonzero) digits is 233280, while the sum is 46.

The square root of 20499985 is about 4527.6909125955. The cubic root of 20499985 is about 273.6851169874.

It can be divided in two parts, 20 and 499985, that added together give a palindrome (500005).

The spelling of 20499985 in words is "twenty million, four hundred ninety-nine thousand, nine hundred eighty-five".