647999663 has 2 divisors, whose sum is σ = 647999664. Its totient is φ = 647999662.

The previous prime is 647999657. The next prime is 647999689. The reversal of 647999663 is 366999746.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-647999663 is a prime.

It is a super-2 number, since 2×647999663² = 839807126496227138, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (647999563) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 323999831 + 323999832.

It is an arithmetic number, because the mean of its divisors is an integer number (323999832).

Almost surely, 2^647999663 is an apocalyptic number.

647999663 is a deficient number, since it is larger than the sum of its proper divisors (1).

647999663 is an equidigital number, since it uses as much as digits as its factorization.

647999663 is an evil number, because the sum of its binary digits is even.

The product of its digits is 13226976, while the sum is 59.

The square root of 647999663 is about 25455.8375034097. The cubic root of 647999663 is about 865.3495921727.

The spelling of 647999663 in words is "six hundred forty-seven million, nine hundred ninety-nine thousand, six hundred sixty-three".