6644695225 has 81 divisors (see below), whose sum is σ = 10256461383. Its totient is φ = 4257039360.

The previous prime is 6644695223. The next prime is 6644695241. The reversal of 6644695225 is 5225964466.

The square root of 6644695225 is 81515.

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 1779911721 + 4864783504 = 42189^2 + 69748^2 .

It is not a de Polignac number, because 6644695225 - 2¹ = 6644695223 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (49).

It is not an unprimeable number, because it can be changed into a prime (6644695223) by changing a digit.

It is a polite number, since it can be written in 80 ways as a sum of consecutive naturals, for example, 48501357 + ... + 48501493.

Almost surely, 2^6644695225 is an apocalyptic number.

6644695225 is the 81515-th square number.

6644695225 is the 40758-th centered octagonal number.

It is an amenable number.

6644695225 is a deficient number, since it is larger than the sum of its proper divisors (3611766158).

6644695225 is a wasteful number, since it uses less digits than its factorization.

6644695225 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 332 (or 166 counting only the distinct ones).

The product of its digits is 3110400, while the sum is 49.

The cubic root of 6644695225 is about 1880.0021903739.

Multiplying 6644695225 by its sum of digits (49), we get a square (325590066025 = 570605²).

6644695225 divided by its sum of digits (49) gives a square (135606025 = 11645²).

It can be divided in two parts, 664 and 4695225, that added together give a square (4695889 = 2167²).

The spelling of 6644695225 in words is "six billion, six hundred forty-four million, six hundred ninety-five thousand, two hundred twenty-five".