647771 has 2 divisors, whose sum is σ = 647772. Its totient is φ = 647770.

The previous prime is 647753. The next prime is 647783. The reversal of 647771 is 177746.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 647771 - 2¹⁴ = 631387 is a prime.

It is a Sophie Germain prime.

It is not a weakly prime, because it can be changed into another prime (647741) 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, 323885 + 323886.

It is an arithmetic number, because the mean of its divisors is an integer number (323886).

2⁶⁴⁷⁷⁷¹ is an apocalyptic number.

647771 is a deficient number, since it is larger than the sum of its proper divisors (1).

647771 is an equidigital number, since it uses as much as digits as its factorization.

647771 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 8232, while the sum is 32.

The square root of 647771 is about 804.8422205625. The cubic root of 647771 is about 86.5247793399.

The spelling of 647771 in words is "six hundred forty-seven thousand, seven hundred seventy-one".