64447945956 has 81 divisors (see below), whose sum is σ = 168837105801. Its totient is φ = 20727651168.

The previous prime is 64447945951. The next prime is 64447945957. The reversal of 64447945956 is 65954974446.

It is a happy number.

The square root of 64447945956 is 253866.

It is a perfect power (a square), and thus also a powerful number.

64447945956 is a `hidden beast` number, since 6 + 4 + 447 + 94 + 59 + 56 = 666.

It can be written as a sum of positive squares in only one way, i.e., 33794939556 + 30653006400 = 183834^2 + 175080^2 .

It is a junction number, because it is equal to n+sod(n) for n = 64447945893 and 64447945902.

It is not an unprimeable number, because it can be changed into a prime (64447945951) 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 26 ways as a sum of consecutive naturals, for example, 44171955 + ... + 44173413.

Almost surely, 2^64447945956 is an apocalyptic number.

64447945956 is the 253866-th square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 64447945956

64447945956 is an abundant number, since it is smaller than the sum of its proper divisors (104389159845).

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

64447945956 is a wasteful number, since it uses less digits than its factorization.

64447945956 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2986 (or 1493 counting only the distinct ones).

The product of its digits is 130636800, while the sum is 63.

It can be divided in two parts, 6444 and 7945956, that added together give a square (7952400 = 2820²).

The spelling of 64447945956 in words is "sixty-four billion, four hundred forty-seven million, nine hundred forty-five thousand, nine hundred fifty-six".