671565971 has 2 divisors, whose sum is σ = 671565972. Its totient is φ = 671565970.

The previous prime is 671565931. The next prime is 671566009. The reversal of 671565971 is 179565176.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 671565971 - 2¹⁸ = 671303827 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (671565901) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 335782985 + 335782986.

It is an arithmetic number, because the mean of its divisors is an integer number (335782986).

Almost surely, 2^671565971 is an apocalyptic number.

671565971 is a deficient number, since it is larger than the sum of its proper divisors (1).

671565971 is an equidigital number, since it uses as much as digits as its factorization.

671565971 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 396900, while the sum is 47.

The square root of 671565971 is about 25914.5899253683. The cubic root of 671565971 is about 875.7152121348.

The spelling of 671565971 in words is "six hundred seventy-one million, five hundred sixty-five thousand, nine hundred seventy-one".