20533440 has 112 divisors (see below), whose sum is σ = 66312288. Its totient is φ = 5382144.

The previous prime is 20533427. The next prime is 20533451. The reversal of 20533440 is 4433502.

It is a happy number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 69934 + ... + 70226.

It is an arithmetic number, because the mean of its divisors is an integer number (592074).

Almost surely, 2^20533440 is an apocalyptic number.

20533440 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 20533440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33156144).

20533440 is an abundant number, since it is smaller than the sum of its proper divisors (45778848).

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

20533440 is a wasteful number, since it uses less digits than its factorization.

20533440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 386 (or 376 counting only the distinct ones).

The product of its (nonzero) digits is 1440, while the sum is 21.

The square root of 20533440 is about 4531.3838945735. The cubic root of 20533440 is about 273.8339164346.

Adding to 20533440 its reverse (4433502), we get a palindrome (24966942).

The spelling of 20533440 in words is "twenty million, five hundred thirty-three thousand, four hundred forty".