18998516 has 6 divisors (see below), whose sum is σ = 33247410. Its totient is φ = 9499256.

The previous prime is 18998491. The next prime is 18998519. The reversal of 18998516 is 61589981.

It can be written as a sum of positive squares in only one way, i.e., 10588516 + 8410000 = 3254^2 + 2900^2 .

It is a super-2 number, since 2×18998516² = 721887220404512, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18998519) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2374811 + ... + 2374818.

It is an arithmetic number, because the mean of its divisors is an integer number (5541235).

Almost surely, 2^18998516 is an apocalyptic number.

It is an amenable number.

18998516 is a deficient number, since it is larger than the sum of its proper divisors (14248894).

18998516 is a wasteful number, since it uses less digits than its factorization.

18998516 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4749633 (or 4749631 counting only the distinct ones).

The product of its digits is 155520, while the sum is 47.

The square root of 18998516 is about 4358.7287137421. The cubic root of 18998516 is about 266.8332174842.

The spelling of 18998516 in words is "eighteen million, nine hundred ninety-eight thousand, five hundred sixteen".