66897644 has 12 divisors (see below), whose sum is σ = 127713768. Its totient is φ = 30408000.

The previous prime is 66897643. The next prime is 66897667. The reversal of 66897644 is 44679866.

It is a junction number, because it is equal to n+sod(n) for n = 66897592 and 66897601.

It is not an unprimeable number, because it can be changed into a prime (66897641) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 760157 + ... + 760244.

It is an arithmetic number, because the mean of its divisors is an integer number (10642814).

Almost surely, 2^66897644 is an apocalyptic number.

It is an amenable number.

66897644 is a deficient number, since it is larger than the sum of its proper divisors (60816124).

66897644 is a wasteful number, since it uses less digits than its factorization.

66897644 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1520416 (or 1520414 counting only the distinct ones).

The product of its digits is 1741824, while the sum is 50.

The square root of 66897644 is about 8179.0979942779. The cubic root of 66897644 is about 405.9478768616.

The spelling of 66897644 in words is "sixty-six million, eight hundred ninety-seven thousand, six hundred forty-four".