21040128000 has 448 divisors, whose sum is σ = 77899199040. Its totient is φ = 5603328000.

The previous prime is 21040127957. The next prime is 21040128061. The reversal of 21040128000 is 82104012.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 27647620 + ... + 27648380.

Almost surely, 2^21040128000 is an apocalyptic number.

21040128000 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 21040128000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (38949599520).

21040128000 is an abundant number, since it is smaller than the sum of its proper divisors (56859071040).

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

21040128000 is an frugal number, since it uses more digits than its factorization.

21040128000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 811 (or 771 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 18.

The spelling of 21040128000 in words is "twenty-one billion, forty million, one hundred twenty-eight thousand".