20104240 has 60 divisors (see below), whose sum is σ = 50648544. Its totient is φ = 7418112.

The previous prime is 20104229. The next prime is 20104241. The reversal of 20104240 is 4240102.

It is a Harshad number since it is a multiple of its sum of digits (13).

It is a self number, because there is not a number n which added to its sum of digits gives 20104240.

It is not an unprimeable number, because it can be changed into a prime (20104241) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 12777 + ... + 14263.

Almost surely, 2^20104240 is an apocalyptic number.

20104240 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 20104240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25324272).

20104240 is an abundant number, since it is smaller than the sum of its proper divisors (30544304).

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

20104240 is a wasteful number, since it uses less digits than its factorization.

20104240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1526 (or 1507 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 13.

The square root of 20104240 is about 4483.7751950784. The cubic root of 20104240 is about 271.9125295442.

Adding to 20104240 its reverse (4240102), we get a palindrome (24344342).

The spelling of 20104240 in words is "twenty million, one hundred four thousand, two hundred forty".