261646776732771 has 32 divisors (see below), whose sum is σ = 389770408722240. Its totient is φ = 173465704742400.

The previous prime is 261646776732661. The next prime is 261646776732791. The reversal of 261646776732771 is 177237677646162.

261646776732771 is a `hidden beast` number, since 2 + 6 + 1 + 6 + 467 + 7 + 6 + 73 + 27 + 71 = 666.

It is not a de Polignac number, because 261646776732771 - 2⁹ = 261646776732259 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 261646776732771.

It is not an unprimeable number, because it can be changed into a prime (261646776732791) 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, 624256251 + ... + 624675243.

It is an arithmetic number, because the mean of its divisors is an integer number (12180325272570).

Almost surely, 2^{261646776732771} is an apocalyptic number.

261646776732771 is a deficient number, since it is larger than the sum of its proper divisors (128123631989469).

261646776732771 is a wasteful number, since it uses less digits than its factorization.

261646776732771 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 546964 (or 546958 counting only the distinct ones).

The product of its digits is 1045529856, while the sum is 72.

The spelling of 261646776732771 in words is "two hundred sixty-one trillion, six hundred forty-six billion, seven hundred seventy-six million, seven hundred thirty-two thousand, seven hundred seventy-one".