21440672 has 48 divisors (see below), whose sum is σ = 48771072. Its totient is φ = 9169920.

The previous prime is 21440647. The next prime is 21440677. The reversal of 21440672 is 27604412.

It is a super-3 number, since 3×21440672³ (a number of 23 digits) contains 333 as substring.

It is not an unprimeable number, because it can be changed into a prime (21440677) 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, 4193 + ... + 7775.

It is an arithmetic number, because the mean of its divisors is an integer number (1016064).

Almost surely, 2^21440672 is an apocalyptic number.

21440672 is a gapful number since it is divisible by the number (22) 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 21440672, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24385536).

21440672 is an abundant number, since it is smaller than the sum of its proper divisors (27330400).

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

21440672 is a wasteful number, since it uses less digits than its factorization.

21440672 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3621 (or 3613 counting only the distinct ones).

The product of its (nonzero) digits is 2688, while the sum is 26.

The square root of 21440672 is about 4630.4073254952. The cubic root of 21440672 is about 277.8088847415.

The spelling of 21440672 in words is "twenty-one million, four hundred forty thousand, six hundred seventy-two".