261598529491 has 8 divisors (see below), whose sum is σ = 281822111424. Its totient is φ = 241389321600.

The previous prime is 261598529431. The next prime is 261598529509. The reversal of 261598529491 is 194925895162.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 261598529491 - 2⁹ = 261598528979 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (261598529431) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3555691 + ... + 3628516.

It is an arithmetic number, because the mean of its divisors is an integer number (35227763928).

Almost surely, 2^261598529491 is an apocalyptic number.

261598529491 is a deficient number, since it is larger than the sum of its proper divisors (20223581933).

261598529491 is a wasteful number, since it uses less digits than its factorization.

261598529491 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7187021.

The product of its digits is 13996800, while the sum is 61.

The spelling of 261598529491 in words is "two hundred sixty-one billion, five hundred ninety-eight million, five hundred twenty-nine thousand, four hundred ninety-one".