21123120300 has 144 divisors (see below), whose sum is σ = 61628868000. Its totient is φ = 5585817600.

The previous prime is 21123120299. The next prime is 21123120367. The reversal of 21123120300 is 302132112.

It is a super-2 number, since 2×21123120300² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a self number, because there is not a number n which added to its sum of digits gives 21123120300.

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 47 ways as a sum of consecutive naturals, for example, 23975860 + ... + 23976740.

It is an arithmetic number, because the mean of its divisors is an integer number (427978250).

Almost surely, 2^21123120300 is an apocalyptic number.

21123120300 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 21123120300, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30814434000).

21123120300 is an abundant number, since it is smaller than the sum of its proper divisors (40505747700).

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

21123120300 is a wasteful number, since it uses less digits than its factorization.

21123120300 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1476 (or 1469 counting only the distinct ones).

The product of its (nonzero) digits is 72, while the sum is 15.

Adding to 21123120300 its reverse (302132112), we get a palindrome (21425252412).

The spelling of 21123120300 in words is "twenty-one billion, one hundred twenty-three million, one hundred twenty thousand, three hundred".