20613320 has 96 divisors (see below), whose sum is σ = 58174200. Its totient is φ = 6515712.

The previous prime is 20613301. The next prime is 20613323. The reversal of 20613320 is 2331602.

It can be written as a sum of positive squares in 4 ways, for example, as 16826404 + 3786916 = 4102^2 + 1946^2 .

It is a super-2 number, since 2×20613320² = 849817922844800, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (20613323) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 25076 + ... + 25884.

Almost surely, 2^20613320 is an apocalyptic number.

20613320 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 20613320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29087100).

20613320 is an abundant number, since it is smaller than the sum of its proper divisors (37560880).

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

20613320 is a wasteful number, since it uses less digits than its factorization.

20613320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 847 (or 836 counting only the distinct ones).

The product of its (nonzero) digits is 216, while the sum is 17.

The square root of 20613320 is about 4540.1894233611. The cubic root of 20613320 is about 274.1885501370.

Adding to 20613320 its reverse (2331602), we get a palindrome (22944922).

The spelling of 20613320 in words is "twenty million, six hundred thirteen thousand, three hundred twenty".