20840085 has 40 divisors (see below), whose sum is σ = 42700416. Its totient is φ = 9525600.

The previous prime is 20840063. The next prime is 20840087. The reversal of 20840085 is 58004802.

It is not a de Polignac number, because 20840085 - 2⁷ = 20839957 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20840087) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 841 + ... + 6510.

Almost surely, 2^20840085 is an apocalyptic number.

It is an amenable number.

20840085 is an abundant number, since it is smaller than the sum of its proper divisors (21860331).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20840085 is an equidigital number, since it uses as much as digits as its factorization.

20840085 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7375 (or 7366 counting only the distinct ones).

The product of its (nonzero) digits is 2560, while the sum is 27.

The square root of 20840085 is about 4565.0941939899. The cubic root of 20840085 is about 275.1903255469.

Adding to 20840085 its reverse (58004802), we get a palindrome (78844887).

The spelling of 20840085 in words is "twenty million, eight hundred forty thousand, eighty-five".