816663671 has 2 divisors, whose sum is σ = 816663672. Its totient is φ = 816663670.

The previous prime is 816663647. The next prime is 816663677. The reversal of 816663671 is 176366618.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 816663671 - 2⁶ = 816663607 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (816663677) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 408331835 + 408331836.

It is an arithmetic number, because the mean of its divisors is an integer number (408331836).

Almost surely, 2^816663671 is an apocalyptic number.

816663671 is a deficient number, since it is larger than the sum of its proper divisors (1).

816663671 is an equidigital number, since it uses as much as digits as its factorization.

816663671 is an evil number, because the sum of its binary digits is even.

The product of its digits is 217728, while the sum is 44.

The square root of 816663671 is about 28577.3279191740. The cubic root of 816663671 is about 934.7190176306.

The spelling of 816663671 in words is "eight hundred sixteen million, six hundred sixty-three thousand, six hundred seventy-one".