21002120200 has 48 divisors (see below), whose sum is σ = 49965529680. Its totient is φ = 8205476160.

The previous prime is 21002120197. The next prime is 21002120213. The reversal of 21002120200 is 202120012.

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

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, 1212454 + ... + 1229653.

It is an arithmetic number, because the mean of its divisors is an integer number (1040948535).

Almost surely, 2^21002120200 is an apocalyptic number.

21002120200 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21002120200 is an abundant number, since it is smaller than the sum of its proper divisors (28963409480).

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

21002120200 is a wasteful number, since it uses less digits than its factorization.

21002120200 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2442166 (or 2442157 counting only the distinct ones).

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

Adding to 21002120200 its reverse (202120012), we get a palindrome (21204240212).

The spelling of 21002120200 in words is "twenty-one billion, two million, one hundred twenty thousand, two hundred".