20644260 has 192 divisors, whose sum is σ = 75264000. Its totient is φ = 4105728.

The previous prime is 20644237. The next prime is 20644303. The reversal of 20644260 is 6244602.

It is a self number, because there is not a number n which added to its sum of digits gives 20644260.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 103641 + ... + 103839.

It is an arithmetic number, because the mean of its divisors is an integer number (392000).

Almost surely, 2^20644260 is an apocalyptic number.

20644260 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 20644260, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (37632000).

20644260 is an abundant number, since it is smaller than the sum of its proper divisors (54619740).

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

20644260 is a wasteful number, since it uses less digits than its factorization.

20644260 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 250 (or 248 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 24.

The square root of 20644260 is about 4543.5954925587. The cubic root of 20644260 is about 274.3256645988.

Adding to 20644260 its reverse (6244602), we get a palindrome (26888862).

The spelling of 20644260 in words is "twenty million, six hundred forty-four thousand, two hundred sixty".