20010840 has 64 divisors (see below), whose sum is σ = 60652800. Its totient is φ = 5281152.

The previous prime is 20010811. The next prime is 20010847. The reversal of 20010840 is 4801002.

It is a Harshad number since it is a multiple of its sum of digits (15).

20010840 is a modest number, since divided by 10840 gives 200 as remainder.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20010847) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 11551 + ... + 13169.

It is an arithmetic number, because the mean of its divisors is an integer number (947700).

Almost surely, 2^20010840 is an apocalyptic number.

20010840 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 20010840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30326400).

20010840 is an abundant number, since it is smaller than the sum of its proper divisors (40641960).

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

20010840 is a wasteful number, since it uses less digits than its factorization.

20010840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1736 (or 1732 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 15.

The square root of 20010840 is about 4473.3477396688. The cubic root of 20010840 is about 271.4907932805.

Adding to 20010840 its reverse (4801002), we get a palindrome (24811842).

The spelling of 20010840 in words is "twenty million, ten thousand, eight hundred forty".