20644200 has 96 divisors (see below), whose sum is σ = 71126400. Its totient is φ = 5503680.

The previous prime is 20644199. The next prime is 20644213. The reversal of 20644200 is 244602.

20644200 is a `hidden beast` number, since 2 + 0 + 644 + 20 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 3489 + ... + 7311.

It is an arithmetic number, because the mean of its divisors is an integer number (740900).

Almost surely, 2^20644200 is an apocalyptic number.

20644200 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 20644200, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35563200).

20644200 is an abundant number, since it is smaller than the sum of its proper divisors (50482200).

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

20644200 is a wasteful number, since it uses less digits than its factorization.

20644200 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3848 (or 3833 counting only the distinct ones).

The product of its (nonzero) digits is 384, while the sum is 18.

The square root of 20644200 is about 4543.5888898535. The cubic root of 20644200 is about 274.3253988339.

Adding to 20644200 its reverse (244602), we get a palindrome (20888802).

The spelling of 20644200 in words is "twenty million, six hundred forty-four thousand, two hundred".