21123331300 has 72 divisors (see below), whose sum is σ = 48888761544. Its totient is φ = 7894179840.

The previous prime is 21123331291. The next prime is 21123331331. The reversal of 21123331300 is 313332112.

It can be written as a sum of positive squares in 12 ways, for example, as 103550976 + 21019780324 = 10176^2 + 144982^2 .

It is an unprimeable number.

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 23 ways as a sum of consecutive naturals, for example, 187552 + ... + 278248.

It is an arithmetic number, because the mean of its divisors is an integer number (679010577).

Almost surely, 2^21123331300 is an apocalyptic number.

21123331300 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 21123331300, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24444380772).

21123331300 is an abundant number, since it is smaller than the sum of its proper divisors (27765430244).

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

21123331300 is a wasteful number, since it uses less digits than its factorization.

21123331300 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 90865 (or 90858 counting only the distinct ones).

The product of its (nonzero) digits is 324, while the sum is 19.

Adding to 21123331300 its reverse (313332112), we get a palindrome (21436663412).

The spelling of 21123331300 in words is "twenty-one billion, one hundred twenty-three million, three hundred thirty-one thousand, three hundred".