18000649 has 2 divisors, whose sum is σ = 18000650. Its totient is φ = 18000648.

The previous prime is 18000643. The next prime is 18000679. The reversal of 18000649 is 94600081.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 16548624 + 1452025 = 4068^2 + 1205^2 .

It is a cyclic number.

It is not a de Polignac number, because 18000649 - 2⁹ = 18000137 is a prime.

It is not a weakly prime, because it can be changed into another prime (18000643) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9000324 + 9000325.

It is an arithmetic number, because the mean of its divisors is an integer number (9000325).

Almost surely, 2^18000649 is an apocalyptic number.

It is an amenable number.

18000649 is a deficient number, since it is larger than the sum of its proper divisors (1).

18000649 is an equidigital number, since it uses as much as digits as its factorization.

18000649 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1728, while the sum is 28.

The square root of 18000649 is about 4242.7171718134. The cubic root of 18000649 is about 262.0772891259.

The spelling of 18000649 in words is "eighteen million, six hundred forty-nine", and thus it is an aban number.