21229448 has 8 divisors (see below), whose sum is σ = 39805230. Its totient is φ = 10614720.

The previous prime is 21229409. The next prime is 21229463. The reversal of 21229448 is 84492212.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 15856324 + 5373124 = 3982^2 + 2318^2 .

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

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1326833 + ... + 1326848.

Almost surely, 2^21229448 is an apocalyptic number.

It is an amenable number.

21229448 is a deficient number, since it is larger than the sum of its proper divisors (18575782).

21229448 is a wasteful number, since it uses less digits than its factorization.

21229448 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2653687 (or 2653683 counting only the distinct ones).

The product of its digits is 9216, while the sum is 32.

The square root of 21229448 is about 4607.5425120122. The cubic root of 21229448 is about 276.8935890887.

The spelling of 21229448 in words is "twenty-one million, two hundred twenty-nine thousand, four hundred forty-eight".