21002021200 has 60 divisors (see below), whose sum is σ = 51065356608. Its totient is φ = 8299580800.

The previous prime is 21002021197. The next prime is 21002021219. The reversal of 21002021200 is 212020012.

It is a Harshad number since it is a multiple of its sum of digits (10).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 283096 + ... + 349495.

Almost surely, 2^21002021200 is an apocalyptic number.

21002021200 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21002021200 is an abundant number, since it is smaller than the sum of its proper divisors (30063335408).

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

21002021200 is a wasteful number, since it uses less digits than its factorization.

21002021200 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 632692 (or 632681 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 10.

Adding to 21002021200 its reverse (212020012), we get a palindrome (21214041212).

The spelling of 21002021200 in words is "twenty-one billion, two million, twenty-one thousand, two hundred".