647666023 has 2 divisors, whose sum is σ = 647666024. Its totient is φ = 647666022.

The previous prime is 647666021. The next prime is 647666057. The reversal of 647666023 is 320666746.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 647666023 - 2¹ = 647666021 is a prime.

Together with 647666021, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (647666021) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 323833011 + 323833012.

It is an arithmetic number, because the mean of its divisors is an integer number (323833012).

Almost surely, 2^647666023 is an apocalyptic number.

647666023 is a deficient number, since it is larger than the sum of its proper divisors (1).

647666023 is an equidigital number, since it uses as much as digits as its factorization.

647666023 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 217728, while the sum is 40.

The square root of 647666023 is about 25449.2833494383. The cubic root of 647666023 is about 865.2010505301.

The spelling of 647666023 in words is "six hundred forty-seven million, six hundred sixty-six thousand, twenty-three".