261231814278 has 12 divisors (see below), whose sum is σ = 566002264308. Its totient is φ = 87077271420.

The previous prime is 261231814273. The next prime is 261231814303. The reversal of 261231814278 is 872418132162.

261231814278 is a `hidden beast` number, since 2 + 61 + 2 + 318 + 1 + 4 + 278 = 666.

It is a super-2 number, since 2×261231814278² (a number of 24 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261231814273) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 7256439268 + ... + 7256439303.

It is an arithmetic number, because the mean of its divisors is an integer number (47166855359).

Almost surely, 2^261231814278 is an apocalyptic number.

261231814278 is an abundant number, since it is smaller than the sum of its proper divisors (304770450030).

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

261231814278 is a wasteful number, since it uses less digits than its factorization.

261231814278 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14512878579 (or 14512878576 counting only the distinct ones).

The product of its digits is 258048, while the sum is 45.

The spelling of 261231814278 in words is "two hundred sixty-one billion, two hundred thirty-one million, eight hundred fourteen thousand, two hundred seventy-eight".