133610561 has 4 divisors (see below), whose sum is σ = 152697792. Its totient is φ = 114523332.

The previous prime is 133610551. The next prime is 133610593. The reversal of 133610561 is 165016331.

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, and also an emirpimes, since its reverse is a distinct semiprime: 165016331 = 17 ⋅9706843.

It is a de Polignac number, because none of the positive numbers 2^k-133610561 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 133610561.

It is not an unprimeable number, because it can be changed into a prime (133610551) 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, 9543605 + ... + 9543618.

It is an arithmetic number, because the mean of its divisors is an integer number (38174448).

Almost surely, 2^133610561 is an apocalyptic number.

It is an amenable number.

133610561 is a deficient number, since it is larger than the sum of its proper divisors (19087231).

133610561 is an equidigital number, since it uses as much as digits as its factorization.

133610561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19087230.

The product of its (nonzero) digits is 1620, while the sum is 26.

The square root of 133610561 is about 11559.0034605064. The cubic root of 133610561 is about 511.2267801100.

Adding to 133610561 its reverse (165016331), we get a palindrome (298626892).

The spelling of 133610561 in words is "one hundred thirty-three million, six hundred ten thousand, five hundred sixty-one".