18129438 has 24 divisors (see below), whose sum is σ = 39651768. Its totient is φ = 5986032.

The previous prime is 18129431. The next prime is 18129443. The reversal of 18129438 is 83492181.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18129431) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2781 + ... + 6632.

It is an arithmetic number, because the mean of its divisors is an integer number (1652157).

Almost surely, 2^18129438 is an apocalyptic number.

18129438 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

18129438 is an abundant number, since it is smaller than the sum of its proper divisors (21522330).

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

18129438 is a wasteful number, since it uses less digits than its factorization.

18129438 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9528 (or 9525 counting only the distinct ones).

The product of its digits is 13824, while the sum is 36.

The square root of 18129438 is about 4257.8677762467. The cubic root of 18129438 is about 262.7008313444.

The spelling of 18129438 in words is "eighteen million, one hundred twenty-nine thousand, four hundred thirty-eight".