646662222397 has 2 divisors, whose sum is σ = 646662222398. Its totient is φ = 646662222396.

The previous prime is 646662222317. The next prime is 646662222449. The reversal of 646662222397 is 793222266646.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 398803617081 + 247858605316 = 631509^2 + 497854^2 .

It is a cyclic number.

It is not a de Polignac number, because 646662222397 - 2¹¹ = 646662220349 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (646662222307) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 323331111198 + 323331111199.

It is an arithmetic number, because the mean of its divisors is an integer number (323331111199).

Almost surely, 2^646662222397 is an apocalyptic number.

It is an amenable number.

646662222397 is a deficient number, since it is larger than the sum of its proper divisors (1).

646662222397 is an equidigital number, since it uses as much as digits as its factorization.

646662222397 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 15676416, while the sum is 55.

The spelling of 646662222397 in words is "six hundred forty-six billion, six hundred sixty-two million, two hundred twenty-two thousand, three hundred ninety-seven".