671265661 has 8 divisors (see below), whose sum is σ = 755912448. Its totient is φ = 590556000.

The previous prime is 671265659. The next prime is 671265667. The reversal of 671265661 is 166562176.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 671265661 - 2¹ = 671265659 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 (671265667) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 983920 + ... + 984601.

It is an arithmetic number, because the mean of its divisors is an integer number (94489056).

Almost surely, 2^671265661 is an apocalyptic number.

It is an amenable number.

671265661 is a deficient number, since it is larger than the sum of its proper divisors (84646787).

671265661 is a wasteful number, since it uses less digits than its factorization.

671265661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1968563.

The product of its digits is 90720, while the sum is 40.

The square root of 671265661 is about 25908.7950511019. The cubic root of 671265661 is about 875.5846589417.

The spelling of 671265661 in words is "six hundred seventy-one million, two hundred sixty-five thousand, six hundred sixty-one".