20104640 has 28 divisors (see below), whose sum is σ = 47874936. Its totient is φ = 8041728.

The previous prime is 20104639. The next prime is 20104657. The reversal of 20104640 is 4640102.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 31094 + ... + 31733.

Almost surely, 2^20104640 is an apocalyptic number.

20104640 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20104640 is an abundant number, since it is smaller than the sum of its proper divisors (27770296).

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

20104640 is an equidigital number, since it uses as much as digits as its factorization.

20104640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 62844 (or 62834 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 17.

The square root of 20104640 is about 4483.8198001258. The cubic root of 20104640 is about 271.9143328833.

Adding to 20104640 its reverse (4640102), we get a palindrome (24744742).

The spelling of 20104640 in words is "twenty million, one hundred four thousand, six hundred forty".