20603220 has 192 divisors, whose sum is σ = 69672960. Its totient is φ = 4492800.

The previous prime is 20603183. The next prime is 20603243. The reversal of 20603220 is 2230602.

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 20603220.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 388714 + ... + 388766.

It is an arithmetic number, because the mean of its divisors is an integer number (362880).

Almost surely, 2^20603220 is an apocalyptic number.

20603220 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 20603220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34836480).

20603220 is an abundant number, since it is smaller than the sum of its proper divisors (49069740).

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

20603220 is a wasteful number, since it uses less digits than its factorization.

20603220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 126 (or 124 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 15.

The square root of 20603220 is about 4539.0769986860. The cubic root of 20603220 is about 274.1437610269.

Adding to 20603220 its reverse (2230602), we get a palindrome (22833822).

The spelling of 20603220 in words is "twenty million, six hundred three thousand, two hundred twenty".