133531609 has 2 divisors, whose sum is σ = 133531610. Its totient is φ = 133531608.

The previous prime is 133531597. The next prime is 133531621. The reversal of 133531609 is 906135331.

It is a balanced prime because it is at equal distance from previous prime (133531597) and next prime (133531621).

It can be written as a sum of positive squares in only one way, i.e., 70090384 + 63441225 = 8372^2 + 7965^2 .

It is an emirp because it is prime and its reverse (906135331) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 133531609 - 2¹⁷ = 133400537 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (133531669) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 66765804 + 66765805.

It is an arithmetic number, because the mean of its divisors is an integer number (66765805).

Almost surely, 2^133531609 is an apocalyptic number.

It is an amenable number.

133531609 is a deficient number, since it is larger than the sum of its proper divisors (1).

133531609 is an equidigital number, since it uses as much as digits as its factorization.

133531609 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 7290, while the sum is 31.

The square root of 133531609 is about 11555.5877825405. The cubic root of 133531609 is about 511.1260636965.

The spelling of 133531609 in words is "one hundred thirty-three million, five hundred thirty-one thousand, six hundred nine".