66444445 has 4 divisors (see below), whose sum is σ = 79733340. Its totient is φ = 53155552.

The previous prime is 66444437. The next prime is 66444461. The reversal of 66444445 is 54444466.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 54444466 = 2 ⋅27222233.

It can be written as a sum of positive squares in 2 ways, for example, as 32467204 + 33977241 = 5698^2 + 5829^2 .

It is a cyclic number.

It is not a de Polignac number, because 66444445 - 2³ = 66444437 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6644440 + ... + 6644449.

It is an arithmetic number, because the mean of its divisors is an integer number (19933335).

Almost surely, 2^66444445 is an apocalyptic number.

It is an amenable number.

66444445 is a deficient number, since it is larger than the sum of its proper divisors (13288895).

66444445 is a wasteful number, since it uses less digits than its factorization.

66444445 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13288894.

The product of its digits is 184320, while the sum is 37.

The square root of 66444445 is about 8151.3462078359. The cubic root of 66444445 is about 405.0290991641.

The spelling of 66444445 in words is "sixty-six million, four hundred forty-four thousand, four hundred forty-five".