18686464 has 20 divisors (see below), whose sum is σ = 37337454. Its totient is φ = 9342976.

The previous prime is 18686461. The next prime is 18686491. The reversal of 18686464 is 46468681.

It can be written as a sum of positive squares in only one way, i.e., 9734400 + 8952064 = 3120^2 + 2992^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 18686464.

It is not an unprimeable number, because it can be changed into a prime (18686461) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 17737 + ... + 18760.

Almost surely, 2^18686464 is an apocalyptic number.

It is an amenable number.

18686464 is a deficient number, since it is larger than the sum of its proper divisors (18650990).

18686464 is an frugal number, since it uses more digits than its factorization.

18686464 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 36515 (or 36499 counting only the distinct ones).

The product of its digits is 221184, while the sum is 43.

The square root of 18686464 is about 4322.7842879330. The cubic root of 18686464 is about 265.3642268235.

The spelling of 18686464 in words is "eighteen million, six hundred eighty-six thousand, four hundred sixty-four".