21266331320 has 96 divisors (see below), whose sum is σ = 52299101520. Its totient is φ = 7778534400.

The previous prime is 21266331209. The next prime is 21266331329. The reversal of 21266331320 is 2313366212.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21266331329) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 708620 + ... + 738020.

Almost surely, 2^21266331320 is an apocalyptic number.

21266331320 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 21266331320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26149550760).

21266331320 is an abundant number, since it is smaller than the sum of its proper divisors (31032770200).

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

21266331320 is a wasteful number, since it uses less digits than its factorization.

21266331320 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 29545 (or 29528 counting only the distinct ones).

The product of its (nonzero) digits is 7776, while the sum is 29.

Adding to 21266331320 its reverse (2313366212), we get a palindrome (23579697532).

The spelling of 21266331320 in words is "twenty-one billion, two hundred sixty-six million, three hundred thirty-one thousand, three hundred twenty".