133693381 has 2 divisors, whose sum is σ = 133693382. Its totient is φ = 133693380.

The previous prime is 133693349. The next prime is 133693403. The reversal of 133693381 is 183396331.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 91508356 + 42185025 = 9566^2 + 6495^2 .

It is an emirp because it is prime and its reverse (183396331) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 133693381 - 2⁵ = 133693349 is a prime.

It is a super-2 number, since 2×133693381² = 35747840246422322, which contains 22 as substring.

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 133693381.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (133693331) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 66846690 + 66846691.

It is an arithmetic number, because the mean of its divisors is an integer number (66846691).

Almost surely, 2^133693381 is an apocalyptic number.

It is an amenable number.

133693381 is a deficient number, since it is larger than the sum of its proper divisors (1).

133693381 is an equidigital number, since it uses as much as digits as its factorization.

133693381 is an evil number, because the sum of its binary digits is even.

The product of its digits is 34992, while the sum is 37.

The square root of 133693381 is about 11562.5853942793. The cubic root of 133693381 is about 511.3323881707.

The spelling of 133693381 in words is "one hundred thirty-three million, six hundred ninety-three thousand, three hundred eighty-one".