20591440 has 120 divisors (see below), whose sum is σ = 54425088. Its totient is φ = 7223040.

The previous prime is 20591407. The next prime is 20591443. The reversal of 20591440 is 4419502.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20591443) by changing a digit.

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 23 ways as a sum of consecutive naturals, for example, 664225 + ... + 664255.

Almost surely, 2^20591440 is an apocalyptic number.

20591440 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 20591440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27212544).

20591440 is an abundant number, since it is smaller than the sum of its proper divisors (33833648).

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

20591440 is a wasteful number, since it uses less digits than its factorization.

20591440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 105 (or 80 counting only the distinct ones).

The product of its (nonzero) digits is 1440, while the sum is 25.

The square root of 20591440 is about 4537.7791925126. The cubic root of 20591440 is about 274.0915033510.

The spelling of 20591440 in words is "twenty million, five hundred ninety-one thousand, four hundred forty".