133564661 has 4 divisors (see below), whose sum is σ = 140594400. Its totient is φ = 126534924.

The previous prime is 133564649. The next prime is 133564663. The reversal of 133564661 is 166465331.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 133564661 - 2¹⁸ = 133302517 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 (133564663) 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, 3514841 + ... + 3514878.

It is an arithmetic number, because the mean of its divisors is an integer number (35148600).

Almost surely, 2^133564661 is an apocalyptic number.

It is an amenable number.

133564661 is a deficient number, since it is larger than the sum of its proper divisors (7029739).

133564661 is an equidigital number, since it uses as much as digits as its factorization.

133564661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7029738.

The product of its digits is 38880, while the sum is 35.

The square root of 133564661 is about 11557.0178246812. The cubic root of 133564661 is about 511.1682318521.

The spelling of 133564661 in words is "one hundred thirty-three million, five hundred sixty-four thousand, six hundred sixty-one".