646145377 has 2 divisors, whose sum is σ = 646145378. Its totient is φ = 646145376.

The previous prime is 646145359. The next prime is 646145441. The reversal of 646145377 is 773541646.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 507871296 + 138274081 = 22536^2 + 11759^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-646145377 is a prime.

It is not a weakly prime, because it can be changed into another prime (646145077) 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, 323072688 + 323072689.

It is an arithmetic number, because the mean of its divisors is an integer number (323072689).

Almost surely, 2^646145377 is an apocalyptic number.

It is an amenable number.

646145377 is a deficient number, since it is larger than the sum of its proper divisors (1).

646145377 is an equidigital number, since it uses as much as digits as its factorization.

646145377 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 423360, while the sum is 43.

The square root of 646145377 is about 25419.3897841785. The cubic root of 646145377 is about 864.5233887456.

It can be divided in two parts, 64 and 6145377, that added together give a square (6145441 = 2479²).

The spelling of 646145377 in words is "six hundred forty-six million, one hundred forty-five thousand, three hundred seventy-seven".