671845081 has 2 divisors, whose sum is σ = 671845082. Its totient is φ = 671845080.

The previous prime is 671845067. The next prime is 671845103. The reversal of 671845081 is 180548176.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 665640000 + 6205081 = 25800^2 + 2491^2 .

It is a cyclic number.

It is not a de Polignac number, because 671845081 - 2¹⁷ = 671714009 is a prime.

It is a super-2 number, since 2×671845081² = 902751625727793122, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (671855081) 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 as a sum of consecutive naturals, namely, 335922540 + 335922541.

It is an arithmetic number, because the mean of its divisors is an integer number (335922541).

Almost surely, 2^671845081 is an apocalyptic number.

It is an amenable number.

671845081 is a deficient number, since it is larger than the sum of its proper divisors (1).

671845081 is an equidigital number, since it uses as much as digits as its factorization.

671845081 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 53760, while the sum is 40.

The square root of 671845081 is about 25919.9745563147. The cubic root of 671845081 is about 875.8365142009.

The spelling of 671845081 in words is "six hundred seventy-one million, eight hundred forty-five thousand, eighty-one".