66544425 has 36 divisors (see below), whose sum is σ = 120456700. Its totient is φ = 35112960.

The previous prime is 66544397. The next prime is 66544459. The reversal of 66544425 is 52444566.

It can be written as a sum of positive squares in 6 ways, for example, as 9753129 + 56791296 = 3123^2 + 7536^2 .

It is not a de Polignac number, because 66544425 - 2⁷ = 66544297 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 66544425.

It is an unprimeable number.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 20301 + ... + 23349.

Almost surely, 2^66544425 is an apocalyptic number.

It is an amenable number.

66544425 is a deficient number, since it is larger than the sum of its proper divisors (53912275).

66544425 is a wasteful number, since it uses less digits than its factorization.

66544425 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3162 (or 3154 counting only the distinct ones).

The product of its digits is 115200, while the sum is 36.

The square root of 66544425 is about 8157.4766319003. The cubic root of 66544425 is about 405.2321485699.

The spelling of 66544425 in words is "sixty-six million, five hundred forty-four thousand, four hundred twenty-five".