644953650491560 has 32 divisors (see below), whose sum is σ = 1527521803797600. Its totient is φ = 244403488607040.

The previous prime is 644953650491509. The next prime is 644953650491569. The reversal of 644953650491560 is 65194056359446.

644953650491560 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a super-2 number, since 2×644953650491560² (a number of 30 digits) contains 22 as substring.

It is a Smith number, since the sum of its digits (67) coincides with the sum of the digits of its prime factors.

It is not an unprimeable number, because it can be changed into a prime (644953650491569) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 424311611406 + ... + 424311612925.

It is an arithmetic number, because the mean of its divisors is an integer number (47735056368675).

Almost surely, 2^{644953650491560} is an apocalyptic number.

It is an amenable number.

644953650491560 is an abundant number, since it is smaller than the sum of its proper divisors (882568153306040).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

644953650491560 is a wasteful number, since it uses less digits than its factorization.

644953650491560 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 848623224361 (or 848623224357 counting only the distinct ones).

The product of its (nonzero) digits is 419904000, while the sum is 67.

The spelling of 644953650491560 in words is "six hundred forty-four trillion, nine hundred fifty-three billion, six hundred fifty million, four hundred ninety-one thousand, five hundred sixty".