18236478 has 48 divisors (see below), whose sum is σ = 41776560. Its totient is φ = 5274624.

The previous prime is 18236473. The next prime is 18236479. The reversal of 18236478 is 87463281.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18236473) 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 23 ways as a sum of consecutive naturals, for example, 22138 + ... + 22946.

It is an arithmetic number, because the mean of its divisors is an integer number (870345).

Almost surely, 2^18236478 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 18236478, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (20888280).

18236478 is an abundant number, since it is smaller than the sum of its proper divisors (23540082).

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

18236478 is a wasteful number, since it uses less digits than its factorization.

18236478 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 861 (or 844 counting only the distinct ones).

The product of its digits is 64512, while the sum is 39.

The square root of 18236478 is about 4270.4189490025. The cubic root of 18236478 is about 263.2168307311.

The spelling of 18236478 in words is "eighteen million, two hundred thirty-six thousand, four hundred seventy-eight".