133403681 has 4 divisors (see below), whose sum is σ = 133606164. Its totient is φ = 133201200.

The previous prime is 133403671. The next prime is 133403689. The reversal of 133403681 is 186304331.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 186304331 = 1607 ⋅115933.

It can be written as a sum of positive squares in 2 ways, for example, as 73805281 + 59598400 = 8591^2 + 7720^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-133403681 is a prime.

It is a super-2 number, since 2×133403681² = 35593084208699522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (133403689) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 100250 + ... + 101571.

It is an arithmetic number, because the mean of its divisors is an integer number (33401541).

Almost surely, 2^133403681 is an apocalyptic number.

It is an amenable number.

133403681 is a deficient number, since it is larger than the sum of its proper divisors (202483).

133403681 is an equidigital number, since it uses as much as digits as its factorization.

133403681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 202482.

The product of its (nonzero) digits is 5184, while the sum is 29.

The square root of 133403681 is about 11550.0511254280. The cubic root of 133403681 is about 510.9627859332.

The spelling of 133403681 in words is "one hundred thirty-three million, four hundred three thousand, six hundred eighty-one".