18640628 has 6 divisors (see below), whose sum is σ = 32621106. Its totient is φ = 9320312.

The previous prime is 18640621. The next prime is 18640639. The reversal of 18640628 is 82604681.

It can be written as a sum of positive squares in only one way, i.e., 13853284 + 4787344 = 3722^2 + 2188^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18640621) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2330075 + ... + 2330082.

It is an arithmetic number, because the mean of its divisors is an integer number (5436851).

Almost surely, 2^18640628 is an apocalyptic number.

It is an amenable number.

18640628 is a deficient number, since it is larger than the sum of its proper divisors (13980478).

18640628 is a wasteful number, since it uses less digits than its factorization.

18640628 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4660161 (or 4660159 counting only the distinct ones).

The product of its (nonzero) digits is 18432, while the sum is 35.

The square root of 18640628 is about 4317.4793572176. The cubic root of 18640628 is about 265.1470786722.

The spelling of 18640628 in words is "eighteen million, six hundred forty thousand, six hundred twenty-eight".