1231332209 has 4 divisors (see below), whose sum is σ = 1284868416. Its totient is φ = 1177796004.

The previous prime is 1231332203. The next prime is 1231332281. The reversal of 1231332209 is 9022331321.

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-1231332209 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (1231332203) 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, 26768069 + ... + 26768114.

It is an arithmetic number, because the mean of its divisors is an integer number (321217104).

Almost surely, 2^1231332209 is an apocalyptic number.

It is an amenable number.

1231332209 is a deficient number, since it is larger than the sum of its proper divisors (53536207).

1231332209 is an equidigital number, since it uses as much as digits as its factorization.

1231332209 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 53536206.

The product of its (nonzero) digits is 1944, while the sum is 26.

The square root of 1231332209 is about 35090.3435292389. The cubic root of 1231332209 is about 1071.8279549701.

The spelling of 1231332209 in words is "one billion, two hundred thirty-one million, three hundred thirty-two thousand, two hundred nine".