18660644 has 6 divisors (see below), whose sum is σ = 32656134. Its totient is φ = 9330320.

The previous prime is 18660643. The next prime is 18660683. The reversal of 18660644 is 44606681.

It can be written as a sum of positive squares in only one way, i.e., 17123044 + 1537600 = 4138^2 + 1240^2 .

It is not an unprimeable number, because it can be changed into a prime (18660643) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2332577 + ... + 2332584.

It is an arithmetic number, because the mean of its divisors is an integer number (5442689).

Almost surely, 2^18660644 is an apocalyptic number.

It is an amenable number.

18660644 is a deficient number, since it is larger than the sum of its proper divisors (13995490).

18660644 is a wasteful number, since it uses less digits than its factorization.

18660644 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4665165 (or 4665163 counting only the distinct ones).

The product of its (nonzero) digits is 27648, while the sum is 35.

The square root of 18660644 is about 4319.7967544782. The cubic root of 18660644 is about 265.2419482490.

The spelling of 18660644 in words is "eighteen million, six hundred sixty thousand, six hundred forty-four".