660542671 has 4 divisors (see below), whose sum is σ = 660921232. Its totient is φ = 660164112.

The previous prime is 660542609. The next prime is 660542683. The reversal of 660542671 is 176245066.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 660542671 - 2⁹ = 660542159 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 660542671.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (660842671) 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, 186651 + ... + 190156.

It is an arithmetic number, because the mean of its divisors is an integer number (165230308).

Almost surely, 2^660542671 is an apocalyptic number.

660542671 is a deficient number, since it is larger than the sum of its proper divisors (378561).

660542671 is a wasteful number, since it uses less digits than its factorization.

660542671 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 378560.

The product of its (nonzero) digits is 60480, while the sum is 37.

The square root of 660542671 is about 25701.0247071980. The cubic root of 660542671 is about 870.8973306467.

The spelling of 660542671 in words is "six hundred sixty million, five hundred forty-two thousand, six hundred seventy-one".