671721171 has 16 divisors (see below), whose sum is σ = 1010741760. Its totient is φ = 393065120.

The previous prime is 671721151. The next prime is 671721173. The reversal of 671721171 is 171127176.

It is a cyclic number.

It is not a de Polignac number, because 671721171 - 2⁹ = 671720659 is a prime.

It is a super-2 number, since 2×671721171² = 902418663139222482, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is not an unprimeable number, because it can be changed into a prime (671721173) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 349995 + ... + 351908.

It is an arithmetic number, because the mean of its divisors is an integer number (63171360).

Almost surely, 2^671721171 is an apocalyptic number.

671721171 is a deficient number, since it is larger than the sum of its proper divisors (339020589).

671721171 is a wasteful number, since it uses less digits than its factorization.

671721171 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 701946.

The product of its digits is 4116, while the sum is 33.

The square root of 671721171 is about 25917.5842045512. The cubic root of 671721171 is about 875.7826666805.

The spelling of 671721171 in words is "six hundred seventy-one million, seven hundred twenty-one thousand, one hundred seventy-one".