20085840 has 160 divisors (see below), whose sum is σ = 73388160. Its totient is φ = 5031936.

The previous prime is 20085839. The next prime is 20085847. The reversal of 20085840 is 4858002.

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 (20085847) 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 31 ways as a sum of consecutive naturals, for example, 36447 + ... + 36993.

It is an arithmetic number, because the mean of its divisors is an integer number (458676).

Almost surely, 2^20085840 is an apocalyptic number.

20085840 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20085840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (36694080).

20085840 is an abundant number, since it is smaller than the sum of its proper divisors (53302320).

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

20085840 is a wasteful number, since it uses less digits than its factorization.

20085840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 586 (or 574 counting only the distinct ones).

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

The square root of 20085840 is about 4481.7228829993. The cubic root of 20085840 is about 271.8295500719.

The spelling of 20085840 in words is "twenty million, eighty-five thousand, eight hundred forty".