18929939 has 4 divisors (see below), whose sum is σ = 21634224. Its totient is φ = 16225656.

The previous prime is 18929923. The next prime is 18929969. The reversal of 18929939 is 93992981.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 18929939 - 2⁴ = 18929923 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18929969) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1352132 + ... + 1352145.

It is an arithmetic number, because the mean of its divisors is an integer number (5408556).

Almost surely, 2^18929939 is an apocalyptic number.

18929939 is a deficient number, since it is larger than the sum of its proper divisors (2704285).

18929939 is an equidigital number, since it uses as much as digits as its factorization.

18929939 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2704284.

The product of its digits is 314928, while the sum is 50.

The square root of 18929939 is about 4350.8549734506. The cubic root of 18929939 is about 266.5117768920.

The spelling of 18929939 in words is "eighteen million, nine hundred twenty-nine thousand, nine hundred thirty-nine".