21001120200 has 72 divisors (see below), whose sum is σ = 70528768050. Its totient is φ = 5600298240.

The previous prime is 21001120193. The next prime is 21001120243. The reversal of 21001120200 is 202110012.

It can be written as a sum of positive squares in 3 ways, for example, as 16114271364 + 4886848836 = 126942^2 + 69906^2 .

It is a tau number, because it is divible by the number of its divisors (72).

It is a Harshad number since it is a multiple of its sum of digits (9).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 5831845 + ... + 5835444.

Almost surely, 2^21001120200 is an apocalyptic number.

21001120200 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21001120200 is an abundant number, since it is smaller than the sum of its proper divisors (49527647850).

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

21001120200 is a wasteful number, since it uses less digits than its factorization.

21001120200 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11667311 (or 11667299 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 9.

Adding to 21001120200 its reverse (202110012), we get a palindrome (21203230212).

The spelling of 21001120200 in words is "twenty-one billion, one million, one hundred twenty thousand, two hundred".