21010001200 has 120 divisors (see below), whose sum is σ = 52364505600. Its totient is φ = 8091310080.

The previous prime is 21010001183. The next prime is 21010001251. The reversal of 21010001200 is 210001012.

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, 4440436 + ... + 4445164.

It is an arithmetic number, because the mean of its divisors is an integer number (436370880).

Almost surely, 2^21010001200 is an apocalyptic number.

21010001200 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 21010001200, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26182252800).

21010001200 is an abundant number, since it is smaller than the sum of its proper divisors (31354504400).

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

21010001200 is a wasteful number, since it uses less digits than its factorization.

21010001200 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5159 (or 5148 counting only the distinct ones).

The product of its (nonzero) digits is 4, while the sum is 7.

Adding to 21010001200 its reverse (210001012), we get a palindrome (21220002212).

The spelling of 21010001200 in words is "twenty-one billion, ten million, one thousand, two hundred".