644641063514 has 16 divisors (see below), whose sum is σ = 1105322292096. Its totient is φ = 276218910000.

The previous prime is 644641063511. The next prime is 644641063541. The reversal of 644641063514 is 415360146446.

It is a happy number.

It is a Smith number, since the sum of its digits (44) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is not an unprimeable number, because it can be changed into a prime (644641063511) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4580837 + ... + 4719464.

It is an arithmetic number, because the mean of its divisors is an integer number (69082643256).

Almost surely, 2^644641063514 is an apocalyptic number.

644641063514 is a deficient number, since it is larger than the sum of its proper divisors (460681228582).

644641063514 is a wasteful number, since it uses less digits than its factorization.

644641063514 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9305261.

The product of its (nonzero) digits is 829440, while the sum is 44.

The spelling of 644641063514 in words is "six hundred forty-four billion, six hundred forty-one million, sixty-three thousand, five hundred fourteen".