21002031200 has 144 divisors (see below), whose sum is σ = 54379581984. Its totient is φ = 7893196800.

The previous prime is 21002031191. The next prime is 21002031221. The reversal of 21002031200 is 213020012.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 12062330 + ... + 12064070.

It is an arithmetic number, because the mean of its divisors is an integer number (377635986).

Almost surely, 2^21002031200 is an apocalyptic number.

21002031200 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 21002031200, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27189790992).

21002031200 is an abundant number, since it is smaller than the sum of its proper divisors (33377550784).

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

21002031200 is a wasteful number, since it uses less digits than its factorization.

21002031200 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2665 (or 2652 counting only the distinct ones).

The product of its (nonzero) digits is 24, while the sum is 11.

Adding to 21002031200 its reverse (213020012), we get a palindrome (21215051212).

The spelling of 21002031200 in words is "twenty-one billion, two million, thirty-one thousand, two hundred".