18394939 has 4 divisors (see below), whose sum is σ = 18411624. Its totient is φ = 18378256.

The previous prime is 18394933. The next prime is 18394951. The reversal of 18394939 is 93949381.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 93949381 = 47 ⋅1998923.

It is a cyclic number.

It is not a de Polignac number, because 18394939 - 2⁹ = 18394427 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18394933) 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, 6562 + ... + 8935.

It is an arithmetic number, because the mean of its divisors is an integer number (4602906).

Almost surely, 2^18394939 is an apocalyptic number.

18394939 is a deficient number, since it is larger than the sum of its proper divisors (16685).

18394939 is a wasteful number, since it uses less digits than its factorization.

18394939 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16684.

The product of its digits is 209952, while the sum is 46.

The square root of 18394939 is about 4288.9321514801. The cubic root of 18394939 is about 263.9770172448.

The spelling of 18394939 in words is "eighteen million, three hundred ninety-four thousand, nine hundred thirty-nine".