133728391 has 2 divisors, whose sum is σ = 133728392. Its totient is φ = 133728390.

The previous prime is 133728383. The next prime is 133728421. The reversal of 133728391 is 193827331.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 133728391 - 2³ = 133728383 is a prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 133728391.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (133728191) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 66864195 + 66864196.

It is an arithmetic number, because the mean of its divisors is an integer number (66864196).

Almost surely, 2^133728391 is an apocalyptic number.

133728391 is a deficient number, since it is larger than the sum of its proper divisors (1).

133728391 is an equidigital number, since it uses as much as digits as its factorization.

133728391 is an evil number, because the sum of its binary digits is even.

The product of its digits is 27216, while the sum is 37.

The square root of 133728391 is about 11564.0992299444. The cubic root of 133728391 is about 511.3770181151.

The spelling of 133728391 in words is "one hundred thirty-three million, seven hundred twenty-eight thousand, three hundred ninety-one".