18363649 has 2 divisors, whose sum is σ = 18363650. Its totient is φ = 18363648.

The previous prime is 18363647. The next prime is 18363659. The reversal of 18363649 is 94636381.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 16459249 + 1904400 = 4057^2 + 1380^2 .

It is a cyclic number.

It is not a de Polignac number, because 18363649 - 2¹ = 18363647 is a prime.

Together with 18363647, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (18363647) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9181824 + 9181825.

It is an arithmetic number, because the mean of its divisors is an integer number (9181825).

Almost surely, 2^18363649 is an apocalyptic number.

It is an amenable number.

18363649 is a deficient number, since it is larger than the sum of its proper divisors (1).

18363649 is an equidigital number, since it uses as much as digits as its factorization.

18363649 is an evil number, because the sum of its binary digits is even.

The product of its digits is 93312, while the sum is 40.

The square root of 18363649 is about 4285.2828378066. The cubic root of 18363649 is about 263.8272563302.

The spelling of 18363649 in words is "eighteen million, three hundred sixty-three thousand, six hundred forty-nine".