21123300000000 has 1296 divisors, whose sum is σ = 79188990705216. Its totient is φ = 4953600000000.

The previous prime is 21123299999941. The next prime is 21123300000013. The reversal of 21123300000000 is 332112.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (12).

It is an unprimeable number.

It is a polite number, since it can be written in 143 ways as a sum of consecutive naturals, for example, 122099999914 + ... + 122100000086.

Almost surely, 2^{21123300000000} is an apocalyptic number.

21123300000000 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 21123300000000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (39594495352608).

21123300000000 is an abundant number, since it is smaller than the sum of its proper divisors (58065690705216).

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

21123300000000 is an frugal number, since it uses more digits than its factorization.

21123300000000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 280 (or 231 counting only the distinct ones).

The product of its (nonzero) digits is 36, while the sum is 12.

Adding to 21123300000000 its reverse (332112), we get a palindrome (21123300332112).

It can be divided in two parts, 2112 and 3300000000, that multiplied together give a square (6969600000000 = 2640000²).

The spelling of 21123300000000 in words is "twenty-one trillion, one hundred twenty-three billion, three hundred million", and thus it is an aban number.