21123210000 has 400 divisors, whose sum is σ = 70954887168. Its totient is φ = 5409600000.

The previous prime is 21123209999. The next prime is 21123210019. The reversal of 21123210000 is 1232112.

It is a tau number, because it is divible by the number of its divisors (400).

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 79 ways as a sum of consecutive naturals, for example, 100109895 + ... + 100110105.

Almost surely, 2^21123210000 is an apocalyptic number.

21123210000 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 21123210000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35477443584).

21123210000 is an abundant number, since it is smaller than the sum of its proper divisors (49831677168).

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

21123210000 is a wasteful number, since it uses less digits than its factorization.

21123210000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 360 (or 339 counting only the distinct ones).

The product of its (nonzero) digits is 24, while the sum is 12.

Adding to 21123210000 its reverse (1232112), we get a palindrome (21124442112).

The spelling of 21123210000 in words is "twenty-one billion, one hundred twenty-three million, two hundred ten thousand".