671221543 has 4 divisors (see below), whose sum is σ = 676506880. Its totient is φ = 665936208.

The previous prime is 671221483. The next prime is 671221547. The reversal of 671221543 is 345122176.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-671221543 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 (671221547) 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, 2642478 + ... + 2642731.

It is an arithmetic number, because the mean of its divisors is an integer number (169126720).

Almost surely, 2^671221543 is an apocalyptic number.

671221543 is a deficient number, since it is larger than the sum of its proper divisors (5285337).

671221543 is a wasteful number, since it uses less digits than its factorization.

671221543 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5285336.

The product of its digits is 10080, while the sum is 31.

The square root of 671221543 is about 25907.9436273897. The cubic root of 671221543 is about 875.5654763276.

The spelling of 671221543 in words is "six hundred seventy-one million, two hundred twenty-one thousand, five hundred forty-three".