261856120461 has 32 divisors (see below), whose sum is σ = 379638483840. Its totient is φ = 159583737600.

The previous prime is 261856120457. The next prime is 261856120531. The reversal of 261856120461 is 164021658162.

It is not a de Polignac number, because 261856120461 - 2² = 261856120457 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261856120441) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 9087006 + ... + 9115776.

It is an arithmetic number, because the mean of its divisors is an integer number (11863702620).

Almost surely, 2^261856120461 is an apocalyptic number.

It is an amenable number.

261856120461 is a deficient number, since it is larger than the sum of its proper divisors (117782363379).

261856120461 is a wasteful number, since it uses less digits than its factorization.

261856120461 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 31037.

The product of its (nonzero) digits is 138240, while the sum is 42.

The spelling of 261856120461 in words is "two hundred sixty-one billion, eight hundred fifty-six million, one hundred twenty thousand, four hundred sixty-one".