671590721 has 2 divisors, whose sum is σ = 671590722. Its totient is φ = 671590720.

The previous prime is 671590691. The next prime is 671590723. The reversal of 671590721 is 127095176.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 619462321 + 52128400 = 24889^2 + 7220^2 .

It is a cyclic number.

It is not a de Polignac number, because 671590721 - 2⁶ = 671590657 is a prime.

Together with 671590723, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (671590723) 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, 335795360 + 335795361.

It is an arithmetic number, because the mean of its divisors is an integer number (335795361).

Almost surely, 2^671590721 is an apocalyptic number.

It is an amenable number.

671590721 is a deficient number, since it is larger than the sum of its proper divisors (1).

671590721 is an equidigital number, since it uses as much as digits as its factorization.

671590721 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 26460, while the sum is 38.

The square root of 671590721 is about 25915.0674511953. The cubic root of 671590721 is about 875.7259699189.

The spelling of 671590721 in words is "six hundred seventy-one million, five hundred ninety thousand, seven hundred twenty-one".