66678445 has 4 divisors (see below), whose sum is σ = 80014140. Its totient is φ = 53342752.

The previous prime is 66678431. The next prime is 66678473. The reversal of 66678445 is 54487666.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 8964036 + 57714409 = 2994^2 + 7597^2 .

It is a cyclic number.

It is not a de Polignac number, because 66678445 - 2⁷ = 66678317 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 66678395 and 66678404.

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, 6667840 + ... + 6667849.

It is an arithmetic number, because the mean of its divisors is an integer number (20003535).

Almost surely, 2^66678445 is an apocalyptic number.

It is an amenable number.

66678445 is a deficient number, since it is larger than the sum of its proper divisors (13335695).

66678445 is a wasteful number, since it uses less digits than its factorization.

66678445 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13335694.

The product of its digits is 967680, while the sum is 46.

The square root of 66678445 is about 8165.6870500895. The cubic root of 66678445 is about 405.5040110329.

The spelling of 66678445 in words is "sixty-six million, six hundred seventy-eight thousand, four hundred forty-five".