20641320 has 96 divisors (see below), whose sum is σ = 76677120. Its totient is φ = 4717440.

The previous prime is 20641307. The next prime is 20641339. The reversal of 20641320 is 2314602.

It is a happy number.

20641320 is a `hidden beast` number, since 2 + 0 + 641 + 3 + 20 = 666.

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

It is a junction number, because it is equal to n+sod(n) for n = 20641293 and 20641302.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1576 + ... + 6615.

It is an arithmetic number, because the mean of its divisors is an integer number (798720).

Almost surely, 2^20641320 is an apocalyptic number.

20641320 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 20641320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (38338560).

20641320 is an abundant number, since it is smaller than the sum of its proper divisors (56035800).

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

20641320 is a wasteful number, since it uses less digits than its factorization.

20641320 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8215 (or 8208 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 18.

The square root of 20641320 is about 4543.2719487171. The cubic root of 20641320 is about 274.3126415156.

Adding to 20641320 its reverse (2314602), we get a palindrome (22955922).

The spelling of 20641320 in words is "twenty million, six hundred forty-one thousand, three hundred twenty".