1131203209 has 16 divisors (see below), whose sum is σ = 1207008000. Its totient is φ = 1057127760.

The previous prime is 1131203201. The next prime is 1131203287. The reversal of 1131203209 is 9023021311.

It is a cyclic number.

It is not a de Polignac number, because 1131203209 - 2³ = 1131203201 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1131203209.

It is not an unprimeable number, because it can be changed into a prime (1131203201) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 444262 + ... + 446800.

It is an arithmetic number, because the mean of its divisors is an integer number (75438000).

Almost surely, 2^1131203209 is an apocalyptic number.

1131203209 is a gapful number since it is divisible by the number (19) formed by its first and last digit.

It is an amenable number.

1131203209 is a deficient number, since it is larger than the sum of its proper divisors (75804791).

1131203209 is a wasteful number, since it uses less digits than its factorization.

1131203209 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2868.

The product of its (nonzero) digits is 324, while the sum is 22.

The square root of 1131203209 is about 33633.3645209634. The cubic root of 1131203209 is about 1041.9499931793.

The spelling of 1131203209 in words is "one billion, one hundred thirty-one million, two hundred three thousand, two hundred nine".