1200100121 has 4 divisors (see below), whose sum is σ = 1309200144. Its totient is φ = 1091000100.

The previous prime is 1200100081. The next prime is 1200100129. The reversal of 1200100121 is 1210010021.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1200100121 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1200100099 and 1200100108.

It is not an unprimeable number, because it can be changed into a prime (1200100129) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 54549995 + ... + 54550016.

It is an arithmetic number, because the mean of its divisors is an integer number (327300036).

Almost surely, 2^1200100121 is an apocalyptic number.

1200100121 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1200100121 is a deficient number, since it is larger than the sum of its proper divisors (109100023).

1200100121 is a wasteful number, since it uses less digits than its factorization.

1200100121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 109100022.

The product of its (nonzero) digits is 4, while the sum is 8.

The square root of 1200100121 is about 34642.4612433932. The cubic root of 1200100121 is about 1062.6881223714.

Adding to 1200100121 its reverse (1210010021), we get a palindrome (2410110142).

The spelling of 1200100121 in words is "one billion, two hundred million, one hundred thousand, one hundred twenty-one".