18136720 has 80 divisors (see below), whose sum is σ = 48746880. Its totient is φ = 6147072.

The previous prime is 18136717. The next prime is 18136721. The reversal of 18136720 is 2763181.

It is a tau number, because it is divible by the number of its divisors (80).

It is a super-2 number, since 2×18136720² = 657881224716800, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (28).

It is not an unprimeable number, because it can be changed into a prime (18136721) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 77724 + ... + 77956.

It is an arithmetic number, because the mean of its divisors is an integer number (609336).

Almost surely, 2^18136720 is an apocalyptic number.

18136720 is a gapful number since it is divisible by the number (10) 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 18136720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24373440).

18136720 is an abundant number, since it is smaller than the sum of its proper divisors (30610160).

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

18136720 is a wasteful number, since it uses less digits than its factorization.

18136720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 392 (or 386 counting only the distinct ones).

The product of its (nonzero) digits is 2016, while the sum is 28.

The square root of 18136720 is about 4258.7228132387. The cubic root of 18136720 is about 262.7359994025.

The spelling of 18136720 in words is "eighteen million, one hundred thirty-six thousand, seven hundred twenty".