644446345036 has 24 divisors (see below), whose sum is σ = 1214803057664. Its totient is φ = 297370759680.

The previous prime is 644446345031. The next prime is 644446345057. The reversal of 644446345036 is 630543644446.

It is a super-2 number, since 2×644446345036² (a number of 24 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (644446345031) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1138380 + ... + 1607731.

Almost surely, 2^644446345036 is an apocalyptic number.

It is an amenable number.

644446345036 is a deficient number, since it is larger than the sum of its proper divisors (570356712628).

644446345036 is a wasteful number, since it uses less digits than its factorization.

644446345036 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2750641 (or 2750639 counting only the distinct ones).

The product of its (nonzero) digits is 9953280, while the sum is 49.

The spelling of 644446345036 in words is "six hundred forty-four billion, four hundred forty-six million, three hundred forty-five thousand, thirty-six".