133706781 has 80 divisors (see below), whose sum is σ = 233365440. Its totient is φ = 75582720.

The previous prime is 133706779. The next prime is 133706801. The reversal of 133706781 is 187607331.

It is not a de Polignac number, because 133706781 - 2¹ = 133706779 is a prime.

It is a super-2 number, since 2×133706781² = 35755006570763922, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (133706701) by changing a digit.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 820206 + ... + 820368.

It is an arithmetic number, because the mean of its divisors is an integer number (2917068).

Almost surely, 2^133706781 is an apocalyptic number.

It is an amenable number.

133706781 is a deficient number, since it is larger than the sum of its proper divisors (99658659).

133706781 is a wasteful number, since it uses less digits than its factorization.

133706781 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 248 (or 239 counting only the distinct ones).

The product of its (nonzero) digits is 21168, while the sum is 36.

The square root of 133706781 is about 11563.1648349403. The cubic root of 133706781 is about 511.3494711034.

The spelling of 133706781 in words is "one hundred thirty-three million, seven hundred six thousand, seven hundred eighty-one".