133431809 has 16 divisors (see below), whose sum is σ = 161317632. Its totient is φ = 107889408.

The previous prime is 133431797. The next prime is 133431811. The reversal of 133431809 is 908134331.

It is a happy number.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-133431809 is a prime.

It is not an unprimeable number, because it can be changed into a prime (133431829) 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, 6077 + ... + 17429.

It is an arithmetic number, because the mean of its divisors is an integer number (10082352).

Almost surely, 2^133431809 is an apocalyptic number.

It is an amenable number.

133431809 is a deficient number, since it is larger than the sum of its proper divisors (27885823).

133431809 is a wasteful number, since it uses less digits than its factorization.

133431809 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11456.

The product of its (nonzero) digits is 7776, while the sum is 32.

The square root of 133431809 is about 11551.2687181971. The cubic root of 133431809 is about 510.9986953652.

The spelling of 133431809 in words is "one hundred thirty-three million, four hundred thirty-one thousand, eight hundred nine".