20903680 has 72 divisors (see below), whose sum is σ = 57248352. Its totient is φ = 7163904.

The previous prime is 20903647. The next prime is 20903681. The reversal of 20903680 is 8630902.

It is a Harshad number since it is a multiple of its sum of digits (28).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20903681) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7794 + ... + 10126.

It is an arithmetic number, because the mean of its divisors is an integer number (795116).

Almost surely, 2^20903680 is an apocalyptic number.

20903680 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 20903680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28624176).

20903680 is an abundant number, since it is smaller than the sum of its proper divisors (36344672).

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

20903680 is an equidigital number, since it uses as much as digits as its factorization.

20903680 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2361 (or 2347 counting only the distinct ones).

The product of its (nonzero) digits is 2592, while the sum is 28.

The square root of 20903680 is about 4572.0542428978. The cubic root of 20903680 is about 275.4699622390.

The spelling of 20903680 in words is "twenty million, nine hundred three thousand, six hundred eighty".