671273721 has 24 divisors (see below), whose sum is σ = 1027962624. Its totient is φ = 421368480.

The previous prime is 671273719. The next prime is 671273723. The reversal of 671273721 is 127372176.

It is an interprime number because it is at equal distance from previous prime (671273719) and next prime (671273723).

It is not a de Polignac number, because 671273721 - 2¹ = 671273719 is a prime.

It is not an unprimeable number, because it can be changed into a prime (671273723) 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 23 ways as a sum of consecutive naturals, for example, 22191 + ... + 42836.

It is an arithmetic number, because the mean of its divisors is an integer number (42831776).

Almost surely, 2^671273721 is an apocalyptic number.

It is an amenable number.

671273721 is a deficient number, since it is larger than the sum of its proper divisors (356688903).

671273721 is a wasteful number, since it uses less digits than its factorization.

671273721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 65101 (or 65098 counting only the distinct ones).

The product of its digits is 24696, while the sum is 36.

The square root of 671273721 is about 25908.9505962708. The cubic root of 671273721 is about 875.5881633586.

The spelling of 671273721 in words is "six hundred seventy-one million, two hundred seventy-three thousand, seven hundred twenty-one".