261752730749 has 4 divisors (see below), whose sum is σ = 261839665920. Its totient is φ = 261665795580.

The previous prime is 261752730683. The next prime is 261752730781. The reversal of 261752730749 is 947037257162.

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 261752730749 - 2²⁰ = 261751682173 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 261752730749.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261752730049) 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, 43463069 + ... + 43469090.

It is an arithmetic number, because the mean of its divisors is an integer number (65459916480).

Almost surely, 2^261752730749 is an apocalyptic number.

It is an amenable number.

261752730749 is a deficient number, since it is larger than the sum of its proper divisors (86935171).

261752730749 is an equidigital number, since it uses as much as digits as its factorization.

261752730749 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 86935170.

The product of its (nonzero) digits is 4445280, while the sum is 53.

The spelling of 261752730749 in words is "two hundred sixty-one billion, seven hundred fifty-two million, seven hundred thirty thousand, seven hundred forty-nine".