21454944 has 72 divisors (see below), whose sum is σ = 65528568. Its totient is φ = 6128640.

The previous prime is 21454943. The next prime is 21454949. The reversal of 21454944 is 44945412.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21454943) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2424 + ... + 6984.

It is an arithmetic number, because the mean of its divisors is an integer number (910119).

Almost surely, 2^21454944 is an apocalyptic number.

21454944 is a gapful number since it is divisible by the number (24) 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 21454944, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32764284).

21454944 is an abundant number, since it is smaller than the sum of its proper divisors (44073624).

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

21454944 is a wasteful number, since it uses less digits than its factorization.

21454944 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4588 (or 4573 counting only the distinct ones).

The product of its digits is 23040, while the sum is 33.

The square root of 21454944 is about 4631.9481862387. The cubic root of 21454944 is about 277.8705123028.

The spelling of 21454944 in words is "twenty-one million, four hundred fifty-four thousand, nine hundred forty-four".