21484518 has 48 divisors (see below), whose sum is σ = 47860848. Its totient is φ = 6424000.

The previous prime is 21484517. The next prime is 21484537. The reversal of 21484518 is 81548412.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21484513) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 73180 + ... + 73472.

It is an arithmetic number, because the mean of its divisors is an integer number (997101).

Almost surely, 2^21484518 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21484518, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23930424).

21484518 is an abundant number, since it is smaller than the sum of its proper divisors (26376330).

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

21484518 is a wasteful number, since it uses less digits than its factorization.

21484518 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 421 (or 410 counting only the distinct ones).

The product of its digits is 10240, while the sum is 33.

The square root of 21484518 is about 4635.1394801020. The cubic root of 21484518 is about 277.9981281036.

It can be divided in two parts, 2148 and 4518, that added together give a palindrome (6666).

The spelling of 21484518 in words is "twenty-one million, four hundred eighty-four thousand, five hundred eighteen".