18139837 has 4 divisors (see below), whose sum is σ = 18151776. Its totient is φ = 18127900.

The previous prime is 18139811. The next prime is 18139859. The reversal of 18139837 is 73893181.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 18139837 - 2²³ = 9751229 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 18139837.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18139897) 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 in 3 ways as a sum of consecutive naturals, for example, 3289 + ... + 6862.

It is an arithmetic number, because the mean of its divisors is an integer number (4537944).

Almost surely, 2^18139837 is an apocalyptic number.

It is an amenable number.

18139837 is a deficient number, since it is larger than the sum of its proper divisors (11939).

18139837 is a wasteful number, since it uses less digits than its factorization.

18139837 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11938.

The product of its digits is 36288, while the sum is 40.

The square root of 18139837 is about 4259.0887523037. The cubic root of 18139837 is about 262.7510499224.

The spelling of 18139837 in words is "eighteen million, one hundred thirty-nine thousand, eight hundred thirty-seven".