21002003000 has 128 divisors (see below), whose sum is σ = 55461931200. Its totient is φ = 7373632000.

The previous prime is 21002002993. The next prime is 21002003003. The reversal of 21002003000 is 30020012.

It is a Harshad number since it is a multiple of its sum of digits (8).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21002003003) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 286082 + ... + 351918.

Almost surely, 2^21002003000 is an apocalyptic number.

21002003000 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 21002003000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27730965600).

21002003000 is an abundant number, since it is smaller than the sum of its proper divisors (34459928200).

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

21002003000 is a wasteful number, since it uses less digits than its factorization.

21002003000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 65898 (or 65884 counting only the distinct ones).

The product of its (nonzero) digits is 12, while the sum is 8.

Adding to 21002003000 its reverse (30020012), we get a palindrome (21032023012).

The spelling of 21002003000 in words is "twenty-one billion, two million, three thousand".