18636481 has 2 divisors, whose sum is σ = 18636482. Its totient is φ = 18636480.

The previous prime is 18636469. The next prime is 18636517. The reversal of 18636481 is 18463681.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 15800625 + 2835856 = 3975^2 + 1684^2 .

It is an emirp because it is prime and its reverse (18463681) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 18636481 - 2¹¹ = 18634433 is a prime.

It is a super-2 number, since 2×18636481² = 694636848126722, which contains 22 as substring.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 18636481.

It is not a weakly prime, because it can be changed into another prime (18636421) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9318240 + 9318241.

It is an arithmetic number, because the mean of its divisors is an integer number (9318241).

Almost surely, 2^18636481 is an apocalyptic number.

It is an amenable number.

18636481 is a deficient number, since it is larger than the sum of its proper divisors (1).

18636481 is an equidigital number, since it uses as much as digits as its factorization.

18636481 is an evil number, because the sum of its binary digits is even.

The product of its digits is 27648, while the sum is 37.

The square root of 18636481 is about 4316.9990734305. Note that the first 3 decimals coincide. The cubic root of 18636481 is about 265.1274146980.

The spelling of 18636481 in words is "eighteen million, six hundred thirty-six thousand, four hundred eighty-one".