646305851 has 2 divisors, whose sum is σ = 646305852. Its totient is φ = 646305850.

The previous prime is 646305841. The next prime is 646305853. The reversal of 646305851 is 158503646.

646305851 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 646305851 - 2¹⁴ = 646289467 is a prime.

It is a super-2 number, since 2×646305851² = 835422506073668402, which contains 22 as substring.

Together with 646305853, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (646305853) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 323152925 + 323152926.

It is an arithmetic number, because the mean of its divisors is an integer number (323152926).

Almost surely, 2^646305851 is an apocalyptic number.

646305851 is a deficient number, since it is larger than the sum of its proper divisors (1).

646305851 is an equidigital number, since it uses as much as digits as its factorization.

646305851 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 86400, while the sum is 38.

The square root of 646305851 is about 25422.5461156038. The cubic root of 646305851 is about 864.5949526422.

The spelling of 646305851 in words is "six hundred forty-six million, three hundred five thousand, eight hundred fifty-one".