646630997 has 2 divisors, whose sum is σ = 646630998. Its totient is φ = 646630996.

The previous prime is 646630979. The next prime is 646631059. The reversal of 646630997 is 799036646.

646630997 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

Together with previous prime (646630979) it forms an Ormiston pair, because they use the same digits, order apart.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 618317956 + 28313041 = 24866^2 + 5321^2 .

It is a cyclic number.

It is not a de Polignac number, because 646630997 - 2¹⁴ = 646614613 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (646630937) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 323315498 + 323315499.

It is an arithmetic number, because the mean of its divisors is an integer number (323315499).

Almost surely, 2^646630997 is an apocalyptic number.

It is an amenable number.

646630997 is a deficient number, since it is larger than the sum of its proper divisors (1).

646630997 is an equidigital number, since it uses as much as digits as its factorization.

646630997 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1469664, while the sum is 50.

The square root of 646630997 is about 25428.9401470057. The cubic root of 646630997 is about 864.7399162385.

The spelling of 646630997 in words is "six hundred forty-six million, six hundred thirty thousand, nine hundred ninety-seven".