133706561 has 4 divisors (see below), whose sum is σ = 135589824. Its totient is φ = 131823300.

The previous prime is 133706557. The next prime is 133706593. The reversal of 133706561 is 165607331.

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 133706561 - 2² = 133706557 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (133706861) 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, 941525 + ... + 941666.

It is an arithmetic number, because the mean of its divisors is an integer number (33897456).

Almost surely, 2^133706561 is an apocalyptic number.

It is an amenable number.

133706561 is a deficient number, since it is larger than the sum of its proper divisors (1883263).

133706561 is an equidigital number, since it uses as much as digits as its factorization.

133706561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1883262.

The product of its (nonzero) digits is 11340, while the sum is 32.

The square root of 133706561 is about 11563.1553219699. The cubic root of 133706561 is about 511.3491906465.

The spelling of 133706561 in words is "one hundred thirty-three million, seven hundred six thousand, five hundred sixty-one".