661056775 has 12 divisors (see below), whose sum is σ = 820041264. Its totient is φ = 528632000.

The previous prime is 661056761. The next prime is 661056779. The reversal of 661056775 is 577650166.

It is not a de Polignac number, because 661056775 - 2⁵ = 661056743 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (661056779) by changing a digit.

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 11 ways as a sum of consecutive naturals, for example, 94395 + ... + 101155.

It is an arithmetic number, because the mean of its divisors is an integer number (68336772).

Almost surely, 2^661056775 is an apocalyptic number.

661056775 is a deficient number, since it is larger than the sum of its proper divisors (158984489).

661056775 is a wasteful number, since it uses less digits than its factorization.

661056775 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10682 (or 10677 counting only the distinct ones).

The product of its (nonzero) digits is 264600, while the sum is 43.

The square root of 661056775 is about 25711.0243864378. The cubic root of 661056775 is about 871.1232134517.

The spelling of 661056775 in words is "six hundred sixty-one million, fifty-six thousand, seven hundred seventy-five".