646627656601 has 2 divisors, whose sum is σ = 646627656602. Its totient is φ = 646627656600.

The previous prime is 646627656599. The next prime is 646627656617. The reversal of 646627656601 is 106656726646.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 636732182025 + 9895474576 = 797955^2 + 99476^2 .

It is a cyclic number.

It is not a de Polignac number, because 646627656601 - 2¹ = 646627656599 is a prime.

Together with 646627656599, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (646627656641) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 323313828300 + 323313828301.

It is an arithmetic number, because the mean of its divisors is an integer number (323313828301).

Almost surely, 2^646627656601 is an apocalyptic number.

It is an amenable number.

646627656601 is a deficient number, since it is larger than the sum of its proper divisors (1).

646627656601 is an equidigital number, since it uses as much as digits as its factorization.

646627656601 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 13063680, while the sum is 55.

The spelling of 646627656601 in words is "six hundred forty-six billion, six hundred twenty-seven million, six hundred fifty-six thousand, six hundred one".