671315180561 has 4 divisors (see below), whose sum is σ = 671345588532. Its totient is φ = 671284772592.

The previous prime is 671315180531. The next prime is 671315180567. The reversal of 671315180561 is 165081513176.

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 624732160000 + 46583020561 = 790400^2 + 215831^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-671315180561 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (671315180567) 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, 15170846 + ... + 15215031.

It is an arithmetic number, because the mean of its divisors is an integer number (167836397133).

Almost surely, 2^671315180561 is an apocalyptic number.

It is an amenable number.

671315180561 is a deficient number, since it is larger than the sum of its proper divisors (30407971).

671315180561 is a wasteful number, since it uses less digits than its factorization.

671315180561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30407970.

The product of its (nonzero) digits is 151200, while the sum is 44.

The spelling of 671315180561 in words is "six hundred seventy-one billion, three hundred fifteen million, one hundred eighty thousand, five hundred sixty-one".