20581344 has 192 divisors, whose sum is σ = 71124480. Its totient is φ = 5667840.

The previous prime is 20581333. The next prime is 20581367. The reversal of 20581344 is 44318502.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 247927 + ... + 248009.

It is an arithmetic number, because the mean of its divisors is an integer number (370440).

Almost surely, 2^20581344 is an apocalyptic number.

20581344 is a gapful number since it is divisible by the number (24) 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 20581344, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35562240).

20581344 is an abundant number, since it is smaller than the sum of its proper divisors (50543136).

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

20581344 is a wasteful number, since it uses less digits than its factorization.

20581344 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 150 (or 136 counting only the distinct ones).

The product of its (nonzero) digits is 3840, while the sum is 27.

The square root of 20581344 is about 4536.6666176831. Note that the first 4 decimals coincide. The cubic root of 20581344 is about 274.0467002646.

Adding to 20581344 its reverse (44318502), we get a palindrome (64899846).

The spelling of 20581344 in words is "twenty million, five hundred eighty-one thousand, three hundred forty-four".