20644316 has 48 divisors (see below), whose sum is σ = 45572352. Its totient is φ = 7948800.

The previous prime is 20644303. The next prime is 20644319. The reversal of 20644316 is 61344602.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20644319) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 29531 + ... + 30221.

It is an arithmetic number, because the mean of its divisors is an integer number (949424).

Almost surely, 2^20644316 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20644316, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22786176).

20644316 is an abundant number, since it is smaller than the sum of its proper divisors (24928036).

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

20644316 is a wasteful number, since it uses less digits than its factorization.

20644316 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 810 (or 808 counting only the distinct ones).

The product of its (nonzero) digits is 3456, while the sum is 26.

The square root of 20644316 is about 4543.6016550750. The cubic root of 20644316 is about 274.3259126455.

Adding to 20644316 its reverse (61344602), we get a palindrome (81988918).

The spelling of 20644316 in words is "twenty million, six hundred forty-four thousand, three hundred sixteen".