20303440 has 40 divisors (see below), whose sum is σ = 49985640. Its totient is φ = 7643136.

The previous prime is 20303431. The next prime is 20303441. The reversal of 20303440 is 4430302.

It can be written as a sum of positive squares in 4 ways, for example, as 7884864 + 12418576 = 2808^2 + 3524^2 .

It is a tau number, because it is divible by the number of its divisors (40).

It is a Harshad number since it is a multiple of its sum of digits (16).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20303441) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6105 + ... + 8824.

It is an arithmetic number, because the mean of its divisors is an integer number (1249641).

Almost surely, 2^20303440 is an apocalyptic number.

20303440 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20303440 is an abundant number, since it is smaller than the sum of its proper divisors (29682200).

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

20303440 is a wasteful number, since it uses less digits than its factorization.

20303440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14959 (or 14953 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 16.

The square root of 20303440 is about 4505.9338654712. The cubic root of 20303440 is about 272.8076484986.

Adding to 20303440 its reverse (4430302), we get a palindrome (24733742).

The spelling of 20303440 in words is "twenty million, three hundred three thousand, four hundred forty".