646222637 has 2 divisors, whose sum is σ = 646222638. Its totient is φ = 646222636.

The previous prime is 646222601. The next prime is 646222669. The reversal of 646222637 is 736222646.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 612513001 + 33709636 = 24749^2 + 5806^2 .

It is a cyclic number.

It is not a de Polignac number, because 646222637 - 2¹² = 646218541 is a prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 646222637.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (646221637) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 323111318 + 323111319.

It is an arithmetic number, because the mean of its divisors is an integer number (323111319).

Almost surely, 2^646222637 is an apocalyptic number.

It is an amenable number.

646222637 is a deficient number, since it is larger than the sum of its proper divisors (1).

646222637 is an equidigital number, since it uses as much as digits as its factorization.

646222637 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 145152, while the sum is 38.

The square root of 646222637 is about 25420.9094447858. The cubic root of 646222637 is about 864.5578445700.

Subtracting 646222637 from its reverse (736222646), we obtain a palindrome (90000009).

The spelling of 646222637 in words is "six hundred forty-six million, two hundred twenty-two thousand, six hundred thirty-seven".