646662293 has 2 divisors, whose sum is σ = 646662294. Its totient is φ = 646662292.

The previous prime is 646662259. The next prime is 646662299. The reversal of 646662293 is 392266646.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 466646404 + 180015889 = 21602^2 + 13417^2 .

It is a cyclic number.

It is not a de Polignac number, because 646662293 - 2¹² = 646658197 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (646662299) 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, 323331146 + 323331147.

It is an arithmetic number, because the mean of its divisors is an integer number (323331147).

Almost surely, 2^646662293 is an apocalyptic number.

It is an amenable number.

646662293 is a deficient number, since it is larger than the sum of its proper divisors (1).

646662293 is an equidigital number, since it uses as much as digits as its factorization.

646662293 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 559872, while the sum is 44.

The square root of 646662293 is about 25429.5555014239. Note that the first 4 decimals coincide. The cubic root of 646662293 is about 864.7538667316.

The spelling of 646662293 in words is "six hundred forty-six million, six hundred sixty-two thousand, two hundred ninety-three".