261856460 has 24 divisors (see below), whose sum is σ = 551939136. Its totient is φ = 104353920.

The previous prime is 261856453. The next prime is 261856487. The reversal of 261856460 is 64658162.

It is a Smith number, since the sum of its digits (38) coincides with the sum of the digits of its prime factors.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 18737 + ... + 29576.

It is an arithmetic number, because the mean of its divisors is an integer number (22997464).

Almost surely, 2^261856460 is an apocalyptic number.

261856460 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

261856460 is an abundant number, since it is smaller than the sum of its proper divisors (290082676).

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

261856460 is a wasteful number, since it uses less digits than its factorization.

261856460 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 48593 (or 48591 counting only the distinct ones).

The product of its (nonzero) digits is 69120, while the sum is 38.

The square root of 261856460 is about 16181.9794833636. The cubic root of 261856460 is about 639.7659137401.

The spelling of 261856460 in words is "two hundred sixty-one million, eight hundred fifty-six thousand, four hundred sixty".