21003840000 has 1600 divisors, whose sum is σ = 96642564480. Its totient is φ = 4423680000.

The previous prime is 21003839977. The next prime is 21003840007. The reversal of 21003840000 is 4830012.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (1600).

It is a super-2 number, since 2×21003840000² (a number of 21 digits) contains 22 as substring.

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 (21003840007) by changing a digit.

It is a polite number, since it can be written in 159 ways as a sum of consecutive naturals, for example, 1235519992 + ... + 1235520008.

Almost surely, 2^21003840000 is an apocalyptic number.

21003840000 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 21003840000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (48321282240).

21003840000 is an abundant number, since it is smaller than the sum of its proper divisors (75638724480).

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

21003840000 is a wasteful number, since it uses less digits than its factorization.

21003840000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 88 (or 51 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 18.

The spelling of 21003840000 in words is "twenty-one billion, three million, eight hundred forty thousand".