18520499 has 4 divisors (see below), whose sum is σ = 18653880. Its totient is φ = 18387120.

The previous prime is 18520493. The next prime is 18520553. The reversal of 18520499 is 99402581.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 99402581 = 761 ⋅130621.

It is a cyclic number.

It is not a de Polignac number, because 18520499 - 2¹⁶ = 18454963 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18520493) 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 in 3 ways as a sum of consecutive naturals, for example, 66482 + ... + 66759.

It is an arithmetic number, because the mean of its divisors is an integer number (4663470).

Almost surely, 2^18520499 is an apocalyptic number.

18520499 is a deficient number, since it is larger than the sum of its proper divisors (133381).

18520499 is a wasteful number, since it uses less digits than its factorization.

18520499 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 133380.

The product of its (nonzero) digits is 25920, while the sum is 38.

The square root of 18520499 is about 4303.5449341212. The cubic root of 18520499 is about 264.5762731137.

The spelling of 18520499 in words is "eighteen million, five hundred twenty thousand, four hundred ninety-nine".