18649643 has 2 divisors, whose sum is σ = 18649644. Its totient is φ = 18649642.

The previous prime is 18649637. The next prime is 18649649. The reversal of 18649643 is 34694681.

It is a balanced prime because it is at equal distance from previous prime (18649637) and next prime (18649649).

It is a cyclic number.

It is not a de Polignac number, because 18649643 - 2⁸ = 18649387 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 18649643.

It is not a weakly prime, because it can be changed into another prime (18649649) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9324821 + 9324822.

It is an arithmetic number, because the mean of its divisors is an integer number (9324822).

Almost surely, 2^18649643 is an apocalyptic number.

18649643 is a deficient number, since it is larger than the sum of its proper divisors (1).

18649643 is an equidigital number, since it uses as much as digits as its factorization.

18649643 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 124416, while the sum is 41.

The square root of 18649643 is about 4318.5232429616. The cubic root of 18649643 is about 265.1898153526.

The spelling of 18649643 in words is "eighteen million, six hundred forty-nine thousand, six hundred forty-three".