261704807961 has 16 divisors (see below), whose sum is σ = 349846128000. Its totient is φ = 174017115008.

The previous prime is 261704807951. The next prime is 261704807983. The reversal of 261704807961 is 169708407162.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-261704807961 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (261704807951) 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, 2400565 + ... + 2507213.

It is an arithmetic number, because the mean of its divisors is an integer number (21865383000).

Almost surely, 2^261704807961 is an apocalyptic number.

It is an amenable number.

261704807961 is a deficient number, since it is larger than the sum of its proper divisors (88141320039).

261704807961 is a wasteful number, since it uses less digits than its factorization.

261704807961 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 108768.

The product of its (nonzero) digits is 1016064, while the sum is 51.

The spelling of 261704807961 in words is "two hundred sixty-one billion, seven hundred four million, eight hundred seven thousand, nine hundred sixty-one".