1201111209 has 12 divisors (see below), whose sum is σ = 1735514352. Its totient is φ = 800475000.

The previous prime is 1201111141. The next prime is 1201111243. The reversal of 1201111209 is 9021111021.

It is a happy number.

It is not a de Polignac number, because 1201111209 - 2⁹ = 1201110697 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1201111191 and 1201111200.

It is not an unprimeable number, because it can be changed into a prime (1201111259) 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, 8734 + ... + 49784.

It is an arithmetic number, because the mean of its divisors is an integer number (144626196).

Almost surely, 2^1201111209 is an apocalyptic number.

It is an amenable number.

1201111209 is a deficient number, since it is larger than the sum of its proper divisors (534403143).

1201111209 is a wasteful number, since it uses less digits than its factorization.

1201111209 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 44308 (or 44305 counting only the distinct ones).

The product of its (nonzero) digits is 36, while the sum is 18.

The square root of 1201111209 is about 34657.0513604375. The cubic root of 1201111209 is about 1062.9864779231.

It can be divided in two parts, 12011 and 11209, that added together give a triangular number (23220 = T₂₁₅).

The spelling of 1201111209 in words is "one billion, two hundred one million, one hundred eleven thousand, two hundred nine".