133199991 has 8 divisors (see below), whose sum is σ = 197333360. Its totient is φ = 88799976.

The previous prime is 133199951. The next prime is 133199999. The reversal of 133199991 is 199991331.

It is not a de Polignac number, because 133199991 - 2⁷ = 133199863 is a prime.

It is a nude number because it is divisible by every one of its digits.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (133199999) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2466640 + ... + 2466693.

It is an arithmetic number, because the mean of its divisors is an integer number (24666670).

Almost surely, 2^133199991 is an apocalyptic number.

133199991 is a deficient number, since it is larger than the sum of its proper divisors (64133369).

133199991 is an equidigital number, since it uses as much as digits as its factorization.

133199991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4933342 (or 4933336 counting only the distinct ones).

The product of its digits is 59049, while the sum is 45.

The square root of 133199991 is about 11541.2300470964. The cubic root of 133199991 is about 510.7025956465.

The spelling of 133199991 in words is "one hundred thirty-three million, one hundred ninety-nine thousand, nine hundred ninety-one".