646424243 has 2 divisors, whose sum is σ = 646424244. Its totient is φ = 646424242.

The previous prime is 646424231. The next prime is 646424279. The reversal of 646424243 is 342424646.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 646424243 - 2⁴ = 646424227 is a prime.

It is not a weakly prime, because it can be changed into another prime (646424143) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 323212121 + 323212122.

It is an arithmetic number, because the mean of its divisors is an integer number (323212122).

Almost surely, 2^646424243 is an apocalyptic number.

646424243 is a deficient number, since it is larger than the sum of its proper divisors (1).

646424243 is an equidigital number, since it uses as much as digits as its factorization.

646424243 is an evil number, because the sum of its binary digits is even.

The product of its digits is 110592, while the sum is 35.

The square root of 646424243 is about 25424.8744932989. The cubic root of 646424243 is about 864.6477423422.

Adding to 646424243 its reverse (342424646), we get a palindrome (988848889).

The spelling of 646424243 in words is "six hundred forty-six million, four hundred twenty-four thousand, two hundred forty-three".