21748472 has 8 divisors (see below), whose sum is σ = 40778400. Its totient is φ = 10874232.

The previous prime is 21748469. The next prime is 21748481. The reversal of 21748472 is 27484712.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (8).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1359272 + ... + 1359287.

It is an arithmetic number, because the mean of its divisors is an integer number (5097300).

Almost surely, 2^21748472 is an apocalyptic number.

It is an amenable number.

21748472 is a deficient number, since it is larger than the sum of its proper divisors (19029928).

21748472 is a wasteful number, since it uses less digits than its factorization.

21748472 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2718565 (or 2718561 counting only the distinct ones).

The product of its digits is 25088, while the sum is 35.

The square root of 21748472 is about 4663.5257048718. The cubic root of 21748472 is about 279.1319716691.

The spelling of 21748472 in words is "twenty-one million, seven hundred forty-eight thousand, four hundred seventy-two".