18520537 has 16 divisors (see below), whose sum is σ = 21676032. Its totient is φ = 15498000.

The previous prime is 18520493. The next prime is 18520553. The reversal of 18520537 is 73502581.

It is not a de Polignac number, because 18520537 - 2¹⁵ = 18487769 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 18520499 and 18520508.

It is not an unprimeable number, because it can be changed into a prime (18520577) 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 15 ways as a sum of consecutive naturals, for example, 73662 + ... + 73912.

It is an arithmetic number, because the mean of its divisors is an integer number (1354752).

Almost surely, 2^18520537 is an apocalyptic number.

18520537 is the 3514-th pentagonal number.

It is an amenable number.

18520537 is a deficient number, since it is larger than the sum of its proper divisors (3155495).

18520537 is a wasteful number, since it uses less digits than its factorization.

18520537 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 468.

The product of its (nonzero) digits is 8400, while the sum is 31.

The square root of 18520537 is about 4303.5493490838. The cubic root of 18520537 is about 264.5764540644.

The spelling of 18520537 in words is "eighteen million, five hundred twenty thousand, five hundred thirty-seven".