261656345503677 has 16 divisors (see below), whose sum is σ = 358582155693120. Its totient is φ = 169591364514432.

The previous prime is 261656345503661. The next prime is 261656345503691. The reversal of 261656345503677 is 776305543656162.

It is a happy number.

It is not a de Polignac number, because 261656345503677 - 2⁴ = 261656345503661 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261656345503697) 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, 914234103 + ... + 914520260.

It is an arithmetic number, because the mean of its divisors is an integer number (22411384730820).

Almost surely, 2^{261656345503677} is an apocalyptic number.

It is an amenable number.

261656345503677 is a deficient number, since it is larger than the sum of its proper divisors (96925810189443).

261656345503677 is a wasteful number, since it uses less digits than its factorization.

261656345503677 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1828755692.

The product of its (nonzero) digits is 571536000, while the sum is 66.

The spelling of 261656345503677 in words is "two hundred sixty-one trillion, six hundred fifty-six billion, three hundred forty-five million, five hundred three thousand, six hundred seventy-seven".