18129672 has 72 divisors (see below), whose sum is σ = 53996670. Its totient is φ = 5491200.

The previous prime is 18129659. The next prime is 18129679. The reversal of 18129672 is 27692181.

It can be written as a sum of positive squares in only one way, i.e., 16208676 + 1920996 = 4026^2 + 1386^2 .

It is a tau number, because it is divible by the number of its divisors (72).

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

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

It is not an unprimeable number, because it can be changed into a prime (18129679) by changing a digit.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 7672 + ... + 9752.

Almost surely, 2^18129672 is an apocalyptic number.

18129672 is a gapful number since it is divisible by the number (12) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 18129672, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26998335).

18129672 is an abundant number, since it is smaller than the sum of its proper divisors (35866998).

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

18129672 is a wasteful number, since it uses less digits than its factorization.

18129672 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2115 (or 2097 counting only the distinct ones).

The product of its digits is 12096, while the sum is 36.

The square root of 18129672 is about 4257.8952547004. The cubic root of 18129672 is about 262.7019615823.

The spelling of 18129672 in words is "eighteen million, one hundred twenty-nine thousand, six hundred seventy-two".