18663929 has 2 divisors, whose sum is σ = 18663930. Its totient is φ = 18663928.

The previous prime is 18663919. The next prime is 18663941. The reversal of 18663929 is 92936681.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 10530025 + 8133904 = 3245^2 + 2852^2 .

It is an emirp because it is prime and its reverse (92936681) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 18663929 - 2⁴ = 18663913 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 18663929.

It is not a weakly prime, because it can be changed into another prime (18663919) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9331964 + 9331965.

It is an arithmetic number, because the mean of its divisors is an integer number (9331965).

Almost surely, 2^18663929 is an apocalyptic number.

It is an amenable number.

18663929 is a deficient number, since it is larger than the sum of its proper divisors (1).

18663929 is an equidigital number, since it uses as much as digits as its factorization.

18663929 is an evil number, because the sum of its binary digits is even.

The product of its digits is 139968, while the sum is 44.

The square root of 18663929 is about 4320.1769639680. The cubic root of 18663929 is about 265.2575116397.

The spelling of 18663929 in words is "eighteen million, six hundred sixty-three thousand, nine hundred twenty-nine".