261023561766 has 48 divisors (see below), whose sum is σ = 619546337280. Its totient is φ = 78767080560.

The previous prime is 261023561761. The next prime is 261023561779. The reversal of 261023561766 is 667165320162.

261023561766 is a `hidden beast` number, since 2 + 6 + 1 + 0 + 23 + 5 + 617 + 6 + 6 = 666.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261023561761) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 2710630 + ... + 2805273.

It is an arithmetic number, because the mean of its divisors is an integer number (12907215360).

Almost surely, 2^261023561766 is an apocalyptic number.

261023561766 is an abundant number, since it is smaller than the sum of its proper divisors (358522775514).

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

261023561766 is a wasteful number, since it uses less digits than its factorization.

261023561766 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5516161 (or 5516158 counting only the distinct ones).

The product of its (nonzero) digits is 544320, while the sum is 45.

The spelling of 261023561766 in words is "two hundred sixty-one billion, twenty-three million, five hundred sixty-one thousand, seven hundred sixty-six".