20017320 has 64 divisors (see below), whose sum is σ = 62000640. Its totient is φ = 5164800.

The previous prime is 20017301. The next prime is 20017357. The reversal of 20017320 is 2371002.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a self number, because there is not a number n which added to its sum of digits gives 20017320.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1030 + ... + 6410.

It is an arithmetic number, because the mean of its divisors is an integer number (968760).

Almost surely, 2^20017320 is an apocalyptic number.

20017320 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 20017320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31000320).

20017320 is an abundant number, since it is smaller than the sum of its proper divisors (41983320).

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

20017320 is a wasteful number, since it uses less digits than its factorization.

20017320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5426 (or 5422 counting only the distinct ones).

The product of its (nonzero) digits is 84, while the sum is 15.

The square root of 20017320 is about 4474.0719708114. The cubic root of 20017320 is about 271.5200952401.

Adding to 20017320 its reverse (2371002), we get a palindrome (22388322).

The spelling of 20017320 in words is "twenty million, seventeen thousand, three hundred twenty".