65671560556561 has 4 divisors (see below), whose sum is σ = 66910646604852. Its totient is φ = 64432474508272.

The previous prime is 65671560556531. The next prime is 65671560556573. The reversal of 65671560556561 is 16565506517656.

It is a happy number.

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

It can be written as a sum of positive squares in 2 ways, for example, as 35913651840000 + 29757908716561 = 5992800^2 + 5455081^2 .

It is a cyclic number.

It is not a de Polignac number, because 65671560556561 - 2²³ = 65671552167953 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 65671560556493 and 65671560556502.

It is not an unprimeable number, because it can be changed into a prime (65671560556531) 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, 619543024066 + ... + 619543024171.

It is an arithmetic number, because the mean of its divisors is an integer number (16727661651213).

Almost surely, 2^{65671560556561} is an apocalyptic number.

It is an amenable number.

65671560556561 is a deficient number, since it is larger than the sum of its proper divisors (1239086048291).

65671560556561 is a wasteful number, since it uses less digits than its factorization.

65671560556561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1239086048290.

The product of its (nonzero) digits is 170100000, while the sum is 64.

The spelling of 65671560556561 in words is "sixty-five trillion, six hundred seventy-one billion, five hundred sixty million, five hundred fifty-six thousand, five hundred sixty-one".