18939629 has 2 divisors, whose sum is σ = 18939630. Its totient is φ = 18939628.

The previous prime is 18939617. The next prime is 18939643. The reversal of 18939629 is 92693981.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 11377129 + 7562500 = 3373^2 + 2750^2 .

It is an emirp because it is prime and its reverse (92693981) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18939629 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18939689) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9469814 + 9469815.

It is an arithmetic number, because the mean of its divisors is an integer number (9469815).

Almost surely, 2^18939629 is an apocalyptic number.

It is an amenable number.

18939629 is a deficient number, since it is larger than the sum of its proper divisors (1).

18939629 is an equidigital number, since it uses as much as digits as its factorization.

18939629 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 209952, while the sum is 47.

The square root of 18939629 is about 4351.9684052162. The cubic root of 18939629 is about 266.5572438213.

The spelling of 18939629 in words is "eighteen million, nine hundred thirty-nine thousand, six hundred twenty-nine".