1200200121 has 6 divisors (see below), whose sum is σ = 1733622410. Its totient is φ = 800133408.

The previous prime is 1200200107. The next prime is 1200200137. The reversal of 1200200121 is 1210020021.

It can be written as a sum of positive squares in only one way, i.e., 1134005625 + 66194496 = 33675^2 + 8136^2 .

It is not a de Polignac number, because 1200200121 - 2¹¹ = 1200198073 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (9), and also a Moran number because the ratio is a prime number: 133355569 = 1200200121 / (1 + 2 + 0 + 0 + 2 + 0 + 0 + 1 + 2 + 1).

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (1200200101) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 66677776 + ... + 66677793.

Almost surely, 2^1200200121 is an apocalyptic number.

It is an amenable number.

1200200121 is a deficient number, since it is larger than the sum of its proper divisors (533422289).

1200200121 is a wasteful number, since it uses less digits than its factorization.

1200200121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 133355575 (or 133355572 counting only the distinct ones).

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

The square root of 1200200121 is about 34643.9045287912. The cubic root of 1200200121 is about 1062.7176382034.

Adding to 1200200121 its reverse (1210020021), we get a palindrome (2410220142).

The spelling of 1200200121 in words is "one billion, two hundred million, two hundred thousand, one hundred twenty-one".