18939329 has 2 divisors, whose sum is σ = 18939330. Its totient is φ = 18939328.

The previous prime is 18939299. The next prime is 18939337. The reversal of 18939329 is 92393981.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 18905104 + 34225 = 4348^2 + 185^2 .

It is a cyclic number.

It is not a de Polignac number, because 18939329 - 2¹⁶ = 18873793 is a prime.

It is a Chen prime.

It is a nialpdrome in base 11.

It is a self number, because there is not a number n which added to its sum of digits gives 18939329.

It is not a weakly prime, because it can be changed into another prime (18939379) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9469664 + 9469665.

It is an arithmetic number, because the mean of its divisors is an integer number (9469665).

Almost surely, 2^18939329 is an apocalyptic number.

It is an amenable number.

18939329 is a deficient number, since it is larger than the sum of its proper divisors (1).

18939329 is an equidigital number, since it uses as much as digits as its factorization.

18939329 is an evil number, because the sum of its binary digits is even.

The product of its digits is 104976, while the sum is 44.

The square root of 18939329 is about 4351.9339379177. The cubic root of 18939329 is about 266.5558364091. Note that the first 3 decimals are identical.

The spelling of 18939329 in words is "eighteen million, nine hundred thirty-nine thousand, three hundred twenty-nine".