64644452257 has 48 divisors (see below), whose sum is σ = 85513300992. Its totient is φ = 47461059360.

The previous prime is 64644452239. The next prime is 64644452261. The reversal of 64644452257 is 75225444646.

It is not a de Polignac number, because 64644452257 - 2¹¹ = 64644450209 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 64644452257.

It is not an unprimeable number, because it can be changed into a prime (64644452207) 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 47 ways as a sum of consecutive naturals, for example, 2717268 + ... + 2740954.

It is an arithmetic number, because the mean of its divisors is an integer number (1781527104).

Almost surely, 2^64644452257 is an apocalyptic number.

64644452257 is a gapful number since it is divisible by the number (67) formed by its first and last digit.

It is an amenable number.

64644452257 is a deficient number, since it is larger than the sum of its proper divisors (20868848735).

64644452257 is a wasteful number, since it uses less digits than its factorization.

64644452257 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23818 (or 23795 counting only the distinct ones).

The product of its digits is 6451200, while the sum is 49.

The spelling of 64644452257 in words is "sixty-four billion, six hundred forty-four million, four hundred fifty-two thousand, two hundred fifty-seven".