20730880 has 44 divisors (see below), whose sum is σ = 49742100. Its totient is φ = 8290304.

The previous prime is 20730869. The next prime is 20730887. The reversal of 20730880 is 8803702.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 6230016 + 14500864 = 2496^2 + 3808^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20730887) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3096 + ... + 7144.

Almost surely, 2^20730880 is an apocalyptic number.

20730880 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 20730880, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24871050).

20730880 is an abundant number, since it is smaller than the sum of its proper divisors (29011220).

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

20730880 is an equidigital number, since it uses as much as digits as its factorization.

20730880 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4074 (or 4056 counting only the distinct ones).

The product of its (nonzero) digits is 2688, while the sum is 28.

The square root of 20730880 is about 4553.1176132404. The cubic root of 20730880 is about 274.7088047121.

The spelling of 20730880 in words is "twenty million, seven hundred thirty thousand, eight hundred eighty".