671643662725 has 72 divisors (see below), whose sum is σ = 995522711040. Its totient is φ = 447870971520.

The previous prime is 671643662713. The next prime is 671643662743. The reversal of 671643662725 is 527266346176.

It is a happy number.

It is not a de Polignac number, because 671643662725 - 2⁹ = 671643662213 is a prime.

It is a super-2 number, since 2×671643662725² (a number of 24 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 143541936 + ... + 143546614.

It is an arithmetic number, because the mean of its divisors is an integer number (13826704320).

Almost surely, 2^671643662725 is an apocalyptic number.

It is an amenable number.

671643662725 is a deficient number, since it is larger than the sum of its proper divisors (323879048315).

671643662725 is a wasteful number, since it uses less digits than its factorization.

671643662725 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7907 (or 7895 counting only the distinct ones).

The product of its digits is 15240960, while the sum is 55.

The spelling of 671643662725 in words is "six hundred seventy-one billion, six hundred forty-three million, six hundred sixty-two thousand, seven hundred twenty-five".