261856102540 has 48 divisors (see below), whose sum is σ = 562404161088. Its totient is φ = 102375313664.

The previous prime is 261856102523. The next prime is 261856102549. The reversal of 261856102540 is 45201658162.

It is a super-3 number, since 3×261856102540³ (a number of 35 digits) contains 333 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 261856102493 and 261856102502.

It is not an unprimeable number, because it can be changed into a prime (261856102549) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 190867 + ... + 748426.

It is an arithmetic number, because the mean of its divisors is an integer number (11716753356).

Almost surely, 2^261856102540 is an apocalyptic number.

261856102540 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

261856102540 is an abundant number, since it is smaller than the sum of its proper divisors (300548058548).

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

261856102540 is a wasteful number, since it uses less digits than its factorization.

261856102540 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 939618 (or 939616 counting only the distinct ones).

The product of its (nonzero) digits is 115200, while the sum is 40.

The spelling of 261856102540 in words is "two hundred sixty-one billion, eight hundred fifty-six million, one hundred two thousand, five hundred forty".