261310133 has 4 divisors (see below), whose sum is σ = 298640160. Its totient is φ = 223980108.

The previous prime is 261310121. The next prime is 261310139. The reversal of 261310133 is 331013162.

It is a happy number.

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 261310133 - 2²⁴ = 244532917 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261310139) 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, 18665003 + ... + 18665016.

It is an arithmetic number, because the mean of its divisors is an integer number (74660040).

Almost surely, 2^261310133 is an apocalyptic number.

It is an amenable number.

261310133 is a deficient number, since it is larger than the sum of its proper divisors (37330027).

261310133 is an equidigital number, since it uses as much as digits as its factorization.

261310133 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 37330026.

The product of its (nonzero) digits is 324, while the sum is 20.

The square root of 261310133 is about 16165.0899471670. The cubic root of 261310133 is about 639.3206764901.

Adding to 261310133 its reverse (331013162), we get a palindrome (592323295).

The spelling of 261310133 in words is "two hundred sixty-one million, three hundred ten thousand, one hundred thirty-three".