20313440 has 72 divisors (see below), whose sum is σ = 55847232. Its totient is φ = 6961920.

The previous prime is 20313437. The next prime is 20313467. The reversal of 20313440 is 4431302.

It is a congruent number.

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 11 ways as a sum of consecutive naturals, for example, 6545 + ... + 9135.

It is an arithmetic number, because the mean of its divisors is an integer number (775656).

Almost surely, 2^20313440 is an apocalyptic number.

20313440 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 20313440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27923616).

20313440 is an abundant number, since it is smaller than the sum of its proper divisors (35533792).

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

20313440 is a wasteful number, since it uses less digits than its factorization.

20313440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2620 (or 2605 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 17.

The square root of 20313440 is about 4507.0433767604. The cubic root of 20313440 is about 272.8524295591.

Adding to 20313440 its reverse (4431302), we get a palindrome (24744742).

The spelling of 20313440 in words is "twenty million, three hundred thirteen thousand, four hundred forty".