133143991 has 2 divisors, whose sum is σ = 133143992. Its totient is φ = 133143990.

The previous prime is 133143973. The next prime is 133144021. The reversal of 133143991 is 199341331.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 133143991 - 2⁷ = 133143863 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (133143931) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 66571995 + 66571996.

It is an arithmetic number, because the mean of its divisors is an integer number (66571996).

Almost surely, 2^133143991 is an apocalyptic number.

133143991 is a deficient number, since it is larger than the sum of its proper divisors (1).

133143991 is an equidigital number, since it uses as much as digits as its factorization.

133143991 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 8748, while the sum is 34.

The square root of 133143991 is about 11538.8037074907. The cubic root of 133143991 is about 510.6310156762.

The spelling of 133143991 in words is "one hundred thirty-three million, one hundred forty-three thousand, nine hundred ninety-one".