20118840 has 128 divisors (see below), whose sum is σ = 70709760. Its totient is φ = 4483584.

The previous prime is 20118811. The next prime is 20118841. The reversal of 20118840 is 4881102.

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a self number, because there is not a number n which added to its sum of digits gives 20118840.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20118841) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 35842 + ... + 36398.

It is an arithmetic number, because the mean of its divisors is an integer number (552420).

Almost surely, 2^20118840 is an apocalyptic number.

20118840 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 20118840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35354880).

20118840 is an abundant number, since it is smaller than the sum of its proper divisors (50590920).

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

20118840 is a wasteful number, since it uses less digits than its factorization.

20118840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 621 (or 617 counting only the distinct ones).

The product of its (nonzero) digits is 512, while the sum is 24.

The square root of 20118840 is about 4485.4029919284. The cubic root of 20118840 is about 271.9783359332.

Adding to 20118840 its reverse (4881102), we get a palindrome (24999942).

The spelling of 20118840 in words is "twenty million, one hundred eighteen thousand, eight hundred forty".