133765661 has 4 divisors (see below), whose sum is σ = 138378300. Its totient is φ = 129153024.

The previous prime is 133765649. The next prime is 133765679. The reversal of 133765661 is 166567331.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 22146436 + 111619225 = 4706^2 + 10565^2 .

It is a cyclic number.

It is not a de Polignac number, because 133765661 - 2¹⁰ = 133764637 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (133765601) 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, 2306276 + ... + 2306333.

It is an arithmetic number, because the mean of its divisors is an integer number (34594575).

Almost surely, 2^133765661 is an apocalyptic number.

It is an amenable number.

133765661 is a deficient number, since it is larger than the sum of its proper divisors (4612639).

133765661 is an equidigital number, since it uses as much as digits as its factorization.

133765661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4612638.

The product of its digits is 68040, while the sum is 38.

The square root of 133765661 is about 11565.7105704751. The cubic root of 133765661 is about 511.4245204967.

The spelling of 133765661 in words is "one hundred thirty-three million, seven hundred sixty-five thousand, six hundred sixty-one".