21133323240 has 128 divisors (see below), whose sum is σ = 64802488320. Its totient is φ = 5512147200.

The previous prime is 21133323209. The next prime is 21133323241. The reversal of 21133323240 is 4232333112.

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a self number, because there is not a number n which added to its sum of digits gives 21133323240.

It is not an unprimeable number, because it can be changed into a prime (21133323241) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1072275 + ... + 1091805.

It is an arithmetic number, because the mean of its divisors is an integer number (506269440).

Almost surely, 2^21133323240 is an apocalyptic number.

21133323240 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 21133323240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32401244160).

21133323240 is an abundant number, since it is smaller than the sum of its proper divisors (43669165080).

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

21133323240 is a wasteful number, since it uses less digits than its factorization.

21133323240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19743 (or 19739 counting only the distinct ones).

The product of its (nonzero) digits is 2592, while the sum is 24.

Adding to 21133323240 its reverse (4232333112), we get a palindrome (25365656352).

The spelling of 21133323240 in words is "twenty-one billion, one hundred thirty-three million, three hundred twenty-three thousand, two hundred forty".