18395521 has 3 divisors (see below), whose sum is σ = 18399811. Its totient is φ = 18391232.

The previous prime is 18395473. The next prime is 18395527. The reversal of 18395521 is 12559381.

The square root of 18395521 is 4289.

It is a perfect power (a square), and thus also a powerful number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in only one way, i.e., 17313921 + 1081600 = 4161^2 + 1040^2 .

It is not a de Polignac number, because 18395521 - 2⁷ = 18395393 is a prime.

It is a super-2 number, since 2×18395521² = 676790385722882, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18395527) by changing a digit.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 2145 + ... + 6433.

Almost surely, 2^18395521 is an apocalyptic number.

18395521 is the 4289-th square number.

18395521 is the 2145-th centered octagonal number.

It is an amenable number.

18395521 is a deficient number, since it is larger than the sum of its proper divisors (4290).

18395521 is an frugal number, since it uses more digits than its factorization.

18395521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8578 (or 4289 counting only the distinct ones).

The product of its digits is 10800, while the sum is 34.

The cubic root of 18395521 is about 263.9798012171.

The spelling of 18395521 in words is "eighteen million, three hundred ninety-five thousand, five hundred twenty-one".