133959781 has 2 divisors, whose sum is σ = 133959782. Its totient is φ = 133959780.

The previous prime is 133959769. The next prime is 133959799. The reversal of 133959781 is 187959331.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 105390756 + 28569025 = 10266^2 + 5345^2 .

It is a cyclic number.

It is not a de Polignac number, because 133959781 - 2⁷ = 133959653 is a prime.

It is a super-2 number, since 2×133959781² = 35890445851135922, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (133959701) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 66979890 + 66979891.

It is an arithmetic number, because the mean of its divisors is an integer number (66979891).

Almost surely, 2^133959781 is an apocalyptic number.

It is an amenable number.

133959781 is a deficient number, since it is larger than the sum of its proper divisors (1).

133959781 is an equidigital number, since it uses as much as digits as its factorization.

133959781 is an evil number, because the sum of its binary digits is even.

The product of its digits is 204120, while the sum is 46.

The square root of 133959781 is about 11574.0995762089. The cubic root of 133959781 is about 511.6717930829.

The spelling of 133959781 in words is "one hundred thirty-three million, nine hundred fifty-nine thousand, seven hundred eighty-one".