18621312 has 64 divisors (see below), whose sum is σ = 50232960. Its totient is φ = 6110720.

The previous prime is 18621301. The next prime is 18621313. The reversal of 18621312 is 21312681.

It is a tau number, because it is divible by the number of its divisors (64).

It is a Harshad number since it is a multiple of its sum of digits (24).

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18621313) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 26923 + ... + 27605.

It is an arithmetic number, because the mean of its divisors is an integer number (784890).

Almost surely, 2^18621312 is an apocalyptic number.

18621312 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 18621312, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25116480).

18621312 is an abundant number, since it is smaller than the sum of its proper divisors (31611648).

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

18621312 is an equidigital number, since it uses as much as digits as its factorization.

18621312 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 771 (or 759 counting only the distinct ones).

The product of its digits is 576, while the sum is 24.

The square root of 18621312 is about 4315.2418240465. The cubic root of 18621312 is about 265.0554624628.

Adding to 18621312 its reverse (21312681), we get a palindrome (39933993).

The spelling of 18621312 in words is "eighteen million, six hundred twenty-one thousand, three hundred twelve".