133506491 has 16 divisors (see below), whose sum is σ = 148347648. Its totient is φ = 119577600.

The previous prime is 133506479. The next prime is 133506493. The reversal of 133506491 is 194605331.

It is a cyclic number.

It is not a de Polignac number, because 133506491 - 2¹⁰ = 133505467 is a prime.

It is a super-3 number, since 3×133506491³ (a number of 25 digits) contains 333 as substring.

It is a Smith number, since the sum of its digits (32) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is not an unprimeable number, because it can be changed into a prime (133506493) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 30071 + ... + 34223.

It is an arithmetic number, because the mean of its divisors is an integer number (9271728).

Almost surely, 2^133506491 is an apocalyptic number.

133506491 is a deficient number, since it is larger than the sum of its proper divisors (14841157).

133506491 is a wasteful number, since it uses less digits than its factorization.

133506491 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4262.

The product of its (nonzero) digits is 9720, while the sum is 32.

The square root of 133506491 is about 11554.5008979185. The cubic root of 133506491 is about 511.0940131839.

The spelling of 133506491 in words is "one hundred thirty-three million, five hundred six thousand, four hundred ninety-one".