21418752 has 54 divisors (see below), whose sum is σ = 57348508. Its totient is φ = 7096832.

The previous prime is 21418751. The next prime is 21418753. The reversal of 21418752 is 25781412.

It is an interprime number because it is at equal distance from previous prime (21418751) and next prime (21418753).

It is not an unprimeable number, because it can be changed into a prime (21418751) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 128173 + ... + 128339.

Almost surely, 2^21418752 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21418752, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28674254).

21418752 is an abundant number, since it is smaller than the sum of its proper divisors (35929756).

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

21418752 is an frugal number, since it uses more digits than its factorization.

21418752 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 353 (or 172 counting only the distinct ones).

The product of its digits is 4480, while the sum is 30.

The square root of 21418752 is about 4628.0397578240. The cubic root of 21418752 is about 277.7141792651.

The spelling of 21418752 in words is "twenty-one million, four hundred eighteen thousand, seven hundred fifty-two".