66563644 has 12 divisors (see below), whose sum is σ = 133127344. Its totient is φ = 28527264.

The previous prime is 66563639. The next prime is 66563689. The reversal of 66563644 is 44636566.

66563644 is an admirable number.

It is a hoax number, since the sum of its digits (40) coincides with the sum of the digits of its distinct prime factors.

It is a junction number, because it is equal to n+sod(n) for n = 66563597 and 66563606.

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, 1188609 + ... + 1188664.

Almost surely, 2^66563644 is an apocalyptic number.

It is an amenable number.

66563644 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

66563644 is a wasteful number, since it uses less digits than its factorization.

66563644 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2377284 (or 2377282 counting only the distinct ones).

The product of its digits is 311040, while the sum is 40.

The square root of 66563644 is about 8158.6545459408. The cubic root of 66563644 is about 405.2711571320.

The spelling of 66563644 in words is "sixty-six million, five hundred sixty-three thousand, six hundred forty-four".