327687721 has 2 divisors, whose sum is σ = 327687722. Its totient is φ = 327687720.

The previous prime is 327687719. The next prime is 327687727. The reversal of 327687721 is 127786723.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 263607696 + 64080025 = 16236^2 + 8005^2 .

It is a cyclic number.

It is not a de Polignac number, because 327687721 - 2¹ = 327687719 is a prime.

Together with 327687719, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (327687727) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 163843860 + 163843861.

It is an arithmetic number, because the mean of its divisors is an integer number (163843861).

Almost surely, 2^327687721 is an apocalyptic number.

It is an amenable number.

327687721 is a deficient number, since it is larger than the sum of its proper divisors (1).

327687721 is an equidigital number, since it uses as much as digits as its factorization.

327687721 is an evil number, because the sum of its binary digits is even.

The product of its digits is 197568, while the sum is 43.

The square root of 327687721 is about 18102.1468616294. The cubic root of 327687721 is about 689.4245156082.

The spelling of 327687721 in words is "three hundred twenty-seven million, six hundred eighty-seven thousand, seven hundred twenty-one".