64991732445025 has 27 divisors (see below), whose sum is σ = 82828617879819. Its totient is φ = 50586998417280.

The previous prime is 64991732444971. The next prime is 64991732445149. The reversal of 64991732445025 is 52054423719946.

The square root of 64991732445025 is 8061745.

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

It can be written as a sum of positive squares in 13 ways, for example, as 28892592283489 + 36099140161536 = 5375183^2 + 6008256^2 .

It is not a de Polignac number, because 64991732445025 - 2⁷ = 64991732444897 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 1491401037 + ... + 1491444613.

Almost surely, 2^{64991732445025} is an apocalyptic number.

64991732445025 is the 8061745-th square number.

64991732445025 is the 4030873-rd centered octagonal number.

It is an amenable number.

64991732445025 is a deficient number, since it is larger than the sum of its proper divisors (17836885434794).

64991732445025 is an frugal number, since it uses more digits than its factorization.

64991732445025 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 87238 (or 43619 counting only the distinct ones).

The product of its (nonzero) digits is 65318400, while the sum is 61.

The spelling of 64991732445025 in words is "sixty-four trillion, nine hundred ninety-one billion, seven hundred thirty-two million, four hundred forty-five thousand, twenty-five".