21232331440 has 80 divisors (see below), whose sum is σ = 51333098400. Its totient is φ = 8157413376.

The previous prime is 21232331383. The next prime is 21232331447. The reversal of 21232331440 is 4413323212.

It is a tau number, because it is divible by the number of its divisors (80).

It is not an unprimeable number, because it can be changed into a prime (21232331447) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 424051 + ... + 471469.

It is an arithmetic number, because the mean of its divisors is an integer number (641663730).

Almost surely, 2^21232331440 is an apocalyptic number.

21232331440 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 21232331440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25666549200).

21232331440 is an abundant number, since it is smaller than the sum of its proper divisors (30100766960).

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

21232331440 is a wasteful number, since it uses less digits than its factorization.

21232331440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 47654 (or 47648 counting only the distinct ones).

The product of its (nonzero) digits is 3456, while the sum is 25.

Adding to 21232331440 its reverse (4413323212), we get a palindrome (25645654652).

The spelling of 21232331440 in words is "twenty-one billion, two hundred thirty-two million, three hundred thirty-one thousand, four hundred forty".