261436873278 has 32 divisors (see below), whose sum is σ = 597762501120. Its totient is φ = 74672186400.

The previous prime is 261436873273. The next prime is 261436873283. The reversal of 261436873278 is 872378634162.

It is an interprime number because it is at equal distance from previous prime (261436873273) and next prime (261436873283).

It is a super-3 number, since 3×261436873278³ (a number of 35 digits) contains 333 as substring.

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

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 870498 + ... + 1131653.

It is an arithmetic number, because the mean of its divisors is an integer number (18680078160).

Almost surely, 2^261436873278 is an apocalyptic number.

261436873278 is an abundant number, since it is smaller than the sum of its proper divisors (336325627842).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

261436873278 is a wasteful number, since it uses less digits than its factorization.

261436873278 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2005272.

The product of its digits is 16257024, while the sum is 57.

The spelling of 261436873278 in words is "two hundred sixty-one billion, four hundred thirty-six million, eight hundred seventy-three thousand, two hundred seventy-eight".