18129816 has 48 divisors (see below), whose sum is σ = 50038560. Its totient is φ = 5928000.

The previous prime is 18129791. The next prime is 18129847. The reversal of 18129816 is 61892181.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a nude number because it is divisible by every one of its digits.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1441 + ... + 6191.

It is an arithmetic number, because the mean of its divisors is an integer number (1042470).

Almost surely, 2^18129816 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 18129816, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25019280).

18129816 is an abundant number, since it is smaller than the sum of its proper divisors (31908744).

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

18129816 is a wasteful number, since it uses less digits than its factorization.

18129816 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4816 (or 4809 counting only the distinct ones).

The product of its digits is 6912, while the sum is 36.

The square root of 18129816 is about 4257.9121644299. The cubic root of 18129816 is about 262.7026571084.

It can be divided in two parts, 1812 and 9816, that added together give a triangular number (11628 = T₁₅₂).

The spelling of 18129816 in words is "eighteen million, one hundred twenty-nine thousand, eight hundred sixteen".