18929917 has 2 divisors, whose sum is σ = 18929918. Its totient is φ = 18929916.

The previous prime is 18929899. The next prime is 18929923. The reversal of 18929917 is 71992981.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 12809241 + 6120676 = 3579^2 + 2474^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18929917 is a prime.

It is a super-3 number, since 3×18929917³ (a number of 23 digits) contains 333 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18929017) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9464958 + 9464959.

It is an arithmetic number, because the mean of its divisors is an integer number (9464959).

Almost surely, 2^18929917 is an apocalyptic number.

It is an amenable number.

18929917 is a deficient number, since it is larger than the sum of its proper divisors (1).

18929917 is an equidigital number, since it uses as much as digits as its factorization.

18929917 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 81648, while the sum is 46.

The square root of 18929917 is about 4350.8524452112. The cubic root of 18929917 is about 266.5116736471.

The spelling of 18929917 in words is "eighteen million, nine hundred twenty-nine thousand, nine hundred seventeen".