66020644 has 6 divisors (see below), whose sum is σ = 115536134. Its totient is φ = 33010320.

The previous prime is 66020641. The next prime is 66020671. The reversal of 66020644 is 44602066.

It can be written as a sum of positive squares in only one way, i.e., 47444544 + 18576100 = 6888^2 + 4310^2 .

It is not an unprimeable number, because it can be changed into a prime (66020641) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8252577 + ... + 8252584.

Almost surely, 2^66020644 is an apocalyptic number.

It is an amenable number.

66020644 is a deficient number, since it is larger than the sum of its proper divisors (49515490).

66020644 is a wasteful number, since it uses less digits than its factorization.

66020644 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16505165 (or 16505163 counting only the distinct ones).

The product of its (nonzero) digits is 6912, while the sum is 28.

The square root of 66020644 is about 8125.3088556682. The cubic root of 66020644 is about 404.1661326997.

The spelling of 66020644 in words is "sixty-six million, twenty thousand, six hundred forty-four".