20643260 has 48 divisors (see below), whose sum is σ = 47803392. Its totient is φ = 7425600.

The previous prime is 20643257. The next prime is 20643269. The reversal of 20643260 is 6234602.

It is a super-2 number, since 2×20643260² = 852288366855200, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20643269) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 22205 + ... + 23115.

It is an arithmetic number, because the mean of its divisors is an integer number (995904).

Almost surely, 2^20643260 is an apocalyptic number.

20643260 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 20643260, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23901696).

20643260 is an abundant number, since it is smaller than the sum of its proper divisors (27160132).

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

20643260 is a wasteful number, since it uses less digits than its factorization.

20643260 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1034 (or 1032 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 23.

The square root of 20643260 is about 4543.4854462186. The cubic root of 20643260 is about 274.3212351174.

Adding to 20643260 its reverse (6234602), we get a palindrome (26877862).

The spelling of 20643260 in words is "twenty million, six hundred forty-three thousand, two hundred sixty".