71667457561 has 16 divisors (see below), whose sum is σ = 83099654784. Its totient is φ = 60539710464.

The previous prime is 71667457513. The next prime is 71667457571. The reversal of 71667457561 is 16575476617.

It is a cyclic number.

It is not a de Polignac number, because 71667457561 - 2⁹ = 71667457049 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (71667457571) 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, 103330 + ... + 392443.

It is an arithmetic number, because the mean of its divisors is an integer number (5193728424).

Almost surely, 2^71667457561 is an apocalyptic number.

It is an amenable number.

71667457561 is a deficient number, since it is larger than the sum of its proper divisors (11432197223).

71667457561 is a wasteful number, since it uses less digits than its factorization.

71667457561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 496080.

The product of its digits is 7408800, while the sum is 55.

The spelling of 71667457561 in words is "seventy-one billion, six hundred sixty-seven million, four hundred fifty-seven thousand, five hundred sixty-one".