64447438225 has 9 divisors (see below), whose sum is σ = 79916397393. Its totient is φ = 51556935120.

The previous prime is 64447438207. The next prime is 64447438229. The reversal of 64447438225 is 52283474446.

The square root of 64447438225 is 253865.

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

It can be written as a sum of positive squares in 4 ways, for example, as 1116695889 + 63330742336 = 33417^2 + 251656^2 .

It is not a de Polignac number, because 64447438225 - 2¹⁷ = 64447307153 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (64447438229) by changing a digit.

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 8 ways as a sum of consecutive naturals, for example, 1243939 + ... + 1294711.

Almost surely, 2^64447438225 is an apocalyptic number.

64447438225 is the 253865-th square number.

64447438225 is the 126933-rd centered octagonal number.

It is an amenable number.

64447438225 is a deficient number, since it is larger than the sum of its proper divisors (15468959168).

64447438225 is an frugal number, since it uses more digits than its factorization.

64447438225 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 101556 (or 50778 counting only the distinct ones).

The product of its digits is 5160960, while the sum is 49.

Multiplying 64447438225 by its sum of digits (49), we get a square (3157924473025 = 1777055²).

The spelling of 64447438225 in words is "sixty-four billion, four hundred forty-seven million, four hundred thirty-eight thousand, two hundred twenty-five".