661256576711 has 4 divisors (see below), whose sum is σ = 661266060000. Its totient is φ = 661247093424.

The previous prime is 661256576671. The next prime is 661256576741. The reversal of 661256576711 is 117675652166.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 661256576711 - 2³⁰ = 660182834887 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 (661256576741) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4636271 + ... + 4776768.

It is an arithmetic number, because the mean of its divisors is an integer number (165316515000).

Almost surely, 2^661256576711 is an apocalyptic number.

661256576711 is a deficient number, since it is larger than the sum of its proper divisors (9483289).

661256576711 is an equidigital number, since it uses as much as digits as its factorization.

661256576711 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9483288.

The product of its digits is 3175200, while the sum is 53.

The spelling of 661256576711 in words is "six hundred sixty-one billion, two hundred fifty-six million, five hundred seventy-six thousand, seven hundred eleven".