261855685124 has 48 divisors (see below), whose sum is σ = 526257889920. Its totient is φ = 112842723840.

The previous prime is 261855685103. The next prime is 261855685219. The reversal of 261855685124 is 421586558162.

It is a happy number.

261855685124 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1030559 + ... + 1259270.

It is an arithmetic number, because the mean of its divisors is an integer number (10963706040).

Almost surely, 2^261855685124 is an apocalyptic number.

It is an amenable number.

261855685124 is an abundant number, since it is smaller than the sum of its proper divisors (264402204796).

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

261855685124 is a wasteful number, since it uses less digits than its factorization.

261855685124 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2289980 (or 2289978 counting only the distinct ones).

The product of its digits is 4608000, while the sum is 53.

The spelling of 261855685124 in words is "two hundred sixty-one billion, eight hundred fifty-five million, six hundred eighty-five thousand, one hundred twenty-four".