66464644 has 6 divisors (see below), whose sum is σ = 116313134. Its totient is φ = 33232320.

The previous prime is 66464639. The next prime is 66464677. The reversal of 66464644 is 44646466.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 40576900 + 25887744 = 6370^2 + 5088^2 .

It is a junction number, because it is equal to n+sod(n) for n = 66464597 and 66464606.

It is an unprimeable number.

It is an upside-down number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8308077 + ... + 8308084.

Almost surely, 2^66464644 is an apocalyptic number.

It is an amenable number.

66464644 is a deficient number, since it is larger than the sum of its proper divisors (49848490).

66464644 is a wasteful number, since it uses less digits than its factorization.

66464644 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16616165 (or 16616163 counting only the distinct ones).

The product of its digits is 331776, while the sum is 40.

The square root of 66464644 is about 8152.5851114846. The cubic root of 66464644 is about 405.0701377284.

The spelling of 66464644 in words is "sixty-six million, four hundred sixty-four thousand, six hundred forty-four".