1200100221 has 12 divisors (see below), whose sum is σ = 1737344700. Its totient is φ = 798282240.

The previous prime is 1200100207. The next prime is 1200100259. The reversal of 1200100221 is 1220010021.

It can be written as a sum of positive squares in 2 ways, for example, as 291077721 + 909022500 = 17061^2 + 30150^2 .

It is not a de Polignac number, because 1200100221 - 2⁹ = 1200099709 is a prime.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1200100721) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 144450 + ... + 152531.

It is an arithmetic number, because the mean of its divisors is an integer number (144778725).

Almost surely, 2^1200100221 is an apocalyptic number.

It is an amenable number.

1200100221 is a deficient number, since it is larger than the sum of its proper divisors (537244479).

1200100221 is a wasteful number, since it uses less digits than its factorization.

1200100221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 297436 (or 297433 counting only the distinct ones).

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

The square root of 1200100221 is about 34642.4626867086. The cubic root of 1200100221 is about 1062.6881518881.

Adding to 1200100221 its reverse (1220010021), we get a palindrome (2420110242).

The spelling of 1200100221 in words is "one billion, two hundred million, one hundred thousand, two hundred twenty-one".