20418280 has 16 divisors (see below), whose sum is σ = 45941220. Its totient is φ = 8167296.

The previous prime is 20418253. The next prime is 20418283. The reversal of 20418280 is 8281402.

It can be written as a sum of positive squares in 2 ways, for example, as 20304036 + 114244 = 4506^2 + 338^2 .

It is not an unprimeable number, because it can be changed into a prime (20418283) 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, 255189 + ... + 255268.

Almost surely, 2^20418280 is an apocalyptic number.

20418280 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20418280 is an abundant number, since it is smaller than the sum of its proper divisors (25522940).

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

20418280 is a wasteful number, since it uses less digits than its factorization.

20418280 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 510468 (or 510464 counting only the distinct ones).

The product of its (nonzero) digits is 1024, while the sum is 25.

The square root of 20418280 is about 4518.6590931381. The cubic root of 20418280 is about 273.3210319006.

Adding to 20418280 its reverse (8281402), we get a palindrome (28699682).

The spelling of 20418280 in words is "twenty million, four hundred eighteen thousand, two hundred eighty".