18909629 has 2 divisors, whose sum is σ = 18909630. Its totient is φ = 18909628.

The previous prime is 18909623. The next prime is 18909673. The reversal of 18909629 is 92690981.

It is an a-pointer prime, because the next prime (18909673) can be obtained adding 18909629 to its sum of digits (44).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 16728100 + 2181529 = 4090^2 + 1477^2 .

It is an emirp because it is prime and its reverse (92690981) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18909629 is a prime.

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 18909629.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18909623) 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, 9454814 + 9454815.

It is an arithmetic number, because the mean of its divisors is an integer number (9454815).

Almost surely, 2^18909629 is an apocalyptic number.

It is an amenable number.

18909629 is a deficient number, since it is larger than the sum of its proper divisors (1).

18909629 is an equidigital number, since it uses as much as digits as its factorization.

18909629 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 69984, while the sum is 44.

The square root of 18909629 is about 4348.5203230524. The cubic root of 18909629 is about 266.4164289678.

The spelling of 18909629 in words is "eighteen million, nine hundred nine thousand, six hundred twenty-nine".