18729438 has 32 divisors (see below), whose sum is σ = 46104576. Its totient is φ = 4939488.

The previous prime is 18729419. The next prime is 18729443. The reversal of 18729438 is 83492781.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is an alternating number because its digits alternate between odd and even.

It is a self number, because there is not a number n which added to its sum of digits gives 18729438.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 16606 + ... + 17697.

It is an arithmetic number, because the mean of its divisors is an integer number (1440768).

Almost surely, 2^18729438 is an apocalyptic number.

18729438 is an abundant number, since it is smaller than the sum of its proper divisors (27375138).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

18729438 is a wasteful number, since it uses less digits than its factorization.

18729438 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 34328.

The product of its digits is 96768, while the sum is 42.

The square root of 18729438 is about 4327.7520723812. The cubic root of 18729438 is about 265.5674939503.

The spelling of 18729438 in words is "eighteen million, seven hundred twenty-nine thousand, four hundred thirty-eight".