21129120000 has 720 divisors, whose sum is σ = 80329036480. Its totient is φ = 5474304000.

The previous prime is 21129119971. The next prime is 21129120007. The reversal of 21129120000 is 2192112.

It is a tau number, because it is divible by the number of its divisors (720).

It is a Harshad number since it is a multiple of its sum of digits (18).

It is not an unprimeable number, because it can be changed into a prime (21129120007) by changing a digit.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 289439964 + ... + 289440036.

Almost surely, 2^21129120000 is an apocalyptic number.

21129120000 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 21129120000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (40164518240).

21129120000 is an abundant number, since it is smaller than the sum of its proper divisors (59199916480).

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

21129120000 is an frugal number, since it uses more digits than its factorization.

21129120000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 185 (or 150 counting only the distinct ones).

The product of its (nonzero) digits is 72, while the sum is 18.

The spelling of 21129120000 in words is "twenty-one billion, one hundred twenty-nine million, one hundred twenty thousand".