18138629 has 2 divisors, whose sum is σ = 18138630. Its totient is φ = 18138628.

The previous prime is 18138623. The next prime is 18138649. The reversal of 18138629 is 92683181.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 9150625 + 8988004 = 3025^2 + 2998^2 .

It is a cyclic number.

It is not a de Polignac number, because 18138629 - 2⁴ = 18138613 is a prime.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 18138592 and 18138601.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18138623) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9069314 + 9069315.

It is an arithmetic number, because the mean of its divisors is an integer number (9069315).

Almost surely, 2^18138629 is an apocalyptic number.

It is an amenable number.

18138629 is a deficient number, since it is larger than the sum of its proper divisors (1).

18138629 is an equidigital number, since it uses as much as digits as its factorization.

18138629 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 20736, while the sum is 38.

The square root of 18138629 is about 4258.9469355699. The cubic root of 18138629 is about 262.7452172659.

The spelling of 18138629 in words is "eighteen million, one hundred thirty-eight thousand, six hundred twenty-nine".