21133210240 has 32 divisors (see below), whose sum is σ = 50521582260. Its totient is φ = 8453283840.

The previous prime is 21133210213. The next prime is 21133210243. The reversal of 21133210240 is 4201233112.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 20362148416 + 771061824 = 142696^2 + 27768^2 .

It is a tau number, because it is divible by the number of its divisors (32).

It is a super-2 number, since 2×21133210240² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21133210243) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 16509681 + ... + 16510960.

Almost surely, 2^21133210240 is an apocalyptic number.

21133210240 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21133210240 is an abundant number, since it is smaller than the sum of its proper divisors (29388372020).

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

21133210240 is an equidigital number, since it uses as much as digits as its factorization.

21133210240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 33020660 (or 33020648 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 19.

Adding to 21133210240 its reverse (4201233112), we get a palindrome (25334443352).

The spelling of 21133210240 in words is "twenty-one billion, one hundred thirty-three million, two hundred ten thousand, two hundred forty".