18913939 has 8 divisors (see below), whose sum is σ = 20666880. Its totient is φ = 17166600.

The previous prime is 18913927. The next prime is 18913969. The reversal of 18913939 is 93931981.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 18913939 - 2⁵ = 18913907 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 18913895 and 18913904.

It is not an unprimeable number, because it can be changed into a prime (18913969) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 9174 + ... + 11044.

It is an arithmetic number, because the mean of its divisors is an integer number (2583360).

Almost surely, 2^18913939 is an apocalyptic number.

18913939 is a deficient number, since it is larger than the sum of its proper divisors (1752941).

18913939 is a wasteful number, since it uses less digits than its factorization.

18913939 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2801.

The product of its digits is 52488, while the sum is 43.

The square root of 18913939 is about 4349.0158656873. The cubic root of 18913939 is about 266.4366685255.

The spelling of 18913939 in words is "eighteen million, nine hundred thirteen thousand, nine hundred thirty-nine".