261436873279 has 4 divisors (see below), whose sum is σ = 262380688984. Its totient is φ = 260493057576.

The previous prime is 261436873273. The next prime is 261436873283. The reversal of 261436873279 is 972378634162.

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 261436873279 - 2¹⁹ = 261436348991 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 (261436873273) 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, 471907437 + ... + 471907990.

It is an arithmetic number, because the mean of its divisors is an integer number (65595172246).

Almost surely, 2^261436873279 is an apocalyptic number.

261436873279 is a deficient number, since it is larger than the sum of its proper divisors (943815705).

261436873279 is an equidigital number, since it uses as much as digits as its factorization.

261436873279 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 943815704.

The product of its digits is 18289152, while the sum is 58.

The spelling of 261436873279 in words is "two hundred sixty-one billion, four hundred thirty-six million, eight hundred seventy-three thousand, two hundred seventy-nine".