20545280 has 72 divisors (see below), whose sum is σ = 56267232. Its totient is φ = 7041024.

The previous prime is 20545277. The next prime is 20545303. The reversal of 20545280 is 8254502.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7814 + ... + 10106.

Almost surely, 2^20545280 is an apocalyptic number.

20545280 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 20545280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28133616).

20545280 is an abundant number, since it is smaller than the sum of its proper divisors (35721952).

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

20545280 is an equidigital number, since it uses as much as digits as its factorization.

20545280 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2321 (or 2307 counting only the distinct ones).

The product of its (nonzero) digits is 3200, while the sum is 26.

The square root of 20545280 is about 4532.6901504515. The cubic root of 20545280 is about 273.8865390606.

Adding to 20545280 its reverse (8254502), we get a palindrome (28799782).

The spelling of 20545280 in words is "twenty million, five hundred forty-five thousand, two hundred eighty".