18513554 has 4 divisors (see below), whose sum is σ = 27770334. Its totient is φ = 9256776.

The previous prime is 18513511. The next prime is 18513559. The reversal of 18513554 is 45531581.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 45531581 = 19 ⋅2396399.

It can be written as a sum of positive squares in only one way, i.e., 18258529 + 255025 = 4273^2 + 505^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 18513554.

It is not an unprimeable number, because it can be changed into a prime (18513559) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4628387 + ... + 4628390.

Almost surely, 2^18513554 is an apocalyptic number.

18513554 is a deficient number, since it is larger than the sum of its proper divisors (9256780).

18513554 is an equidigital number, since it uses as much as digits as its factorization.

18513554 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9256779.

The product of its digits is 12000, while the sum is 32.

The square root of 18513554 is about 4302.7379655285. The cubic root of 18513554 is about 264.5431978359.

The spelling of 18513554 in words is "eighteen million, five hundred thirteen thousand, five hundred fifty-four".