261888134479 has 4 divisors (see below), whose sum is σ = 262232272080. Its totient is φ = 261543996880.

The previous prime is 261888134461. The next prime is 261888134503. The reversal of 261888134479 is 974431888162.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 261888134479 - 2¹³ = 261888126287 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261888132479) 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, 172067659 + ... + 172069180.

It is an arithmetic number, because the mean of its divisors is an integer number (65558068020).

Almost surely, 2^261888134479 is an apocalyptic number.

261888134479 is a deficient number, since it is larger than the sum of its proper divisors (344137601).

261888134479 is an equidigital number, since it uses as much as digits as its factorization.

261888134479 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 344137600.

The product of its digits is 18579456, while the sum is 61.

The spelling of 261888134479 in words is "two hundred sixty-one billion, eight hundred eighty-eight million, one hundred thirty-four thousand, four hundred seventy-nine".