21447344 has 10 divisors (see below), whose sum is σ = 41554260. Its totient is φ = 10723664.

The previous prime is 21447341. The next prime is 21447359. The reversal of 21447344 is 44374412.

It is not an unprimeable number, because it can be changed into a prime (21447341) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 670214 + ... + 670245.

It is an arithmetic number, because the mean of its divisors is an integer number (4155426).

Almost surely, 2^21447344 is an apocalyptic number.

It is an amenable number.

21447344 is a deficient number, since it is larger than the sum of its proper divisors (20106916).

21447344 is a wasteful number, since it uses less digits than its factorization.

21447344 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1340467 (or 1340461 counting only the distinct ones).

The product of its digits is 10752, while the sum is 29.

The square root of 21447344 is about 4631.1277244317. The cubic root of 21447344 is about 277.8376983386.

The spelling of 21447344 in words is "twenty-one million, four hundred forty-seven thousand, three hundred forty-four".