20417280 has 144 divisors (see below), whose sum is σ = 70395360. Its totient is φ = 5013504.

The previous prime is 20417269. The next prime is 20417281. The reversal of 20417280 is 8271402.

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a self number, because there is not a number n which added to its sum of digits gives 20417280.

It is not an unprimeable number, because it can be changed into a prime (20417281) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 49716 + ... + 50124.

Almost surely, 2^20417280 is an apocalyptic number.

20417280 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 20417280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35197680).

20417280 is an abundant number, since it is smaller than the sum of its proper divisors (49978080).

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

20417280 is a wasteful number, since it uses less digits than its factorization.

20417280 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 446 (or 432 counting only the distinct ones).

The product of its (nonzero) digits is 896, while the sum is 24.

The square root of 20417280 is about 4518.5484394881. The cubic root of 20417280 is about 273.3165697962.

Adding to 20417280 its reverse (8271402), we get a palindrome (28688682).

The spelling of 20417280 in words is "twenty million, four hundred seventeen thousand, two hundred eighty".