20644160 has 28 divisors (see below), whose sum is σ = 49159668. Its totient is φ = 8257536.

The previous prime is 20644157. The next prime is 20644177. The reversal of 20644160 is 6144602.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 5837056 + 14807104 = 2416^2 + 3848^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 31937 + ... + 32576.

Almost surely, 2^20644160 is an apocalyptic number.

20644160 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20644160 is an abundant number, since it is smaller than the sum of its proper divisors (28515508).

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

20644160 is an equidigital number, since it uses as much as digits as its factorization.

20644160 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 64530 (or 64520 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 23.

The square root of 20644160 is about 4543.5844880447. The cubic root of 20644160 is about 274.3252216571.

Adding to 20644160 its reverse (6144602), we get a palindrome (26788762).

The spelling of 20644160 in words is "twenty million, six hundred forty-four thousand, one hundred sixty".