18495821 has 2 divisors, whose sum is σ = 18495822. Its totient is φ = 18495820.

The previous prime is 18495811. The next prime is 18495853. The reversal of 18495821 is 12859481.

18495821 is nontrivially palindromic in base 5.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18369796 + 126025 = 4286^2 + 355^2 .

It is an emirp because it is prime and its reverse (12859481) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 18495821 - 2¹⁰ = 18494797 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18495811) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9247910 + 9247911.

It is an arithmetic number, because the mean of its divisors is an integer number (9247911).

Almost surely, 2^18495821 is an apocalyptic number.

It is an amenable number.

18495821 is a deficient number, since it is larger than the sum of its proper divisors (1).

18495821 is an equidigital number, since it uses as much as digits as its factorization.

18495821 is an evil number, because the sum of its binary digits is even.

The product of its digits is 23040, while the sum is 38.

The square root of 18495821 is about 4300.6768072014. The cubic root of 18495821 is about 264.4587076095.

The spelling of 18495821 in words is "eighteen million, four hundred ninety-five thousand, eight hundred twenty-one".