21232144 has 10 divisors (see below), whose sum is σ = 41137310. Its totient is φ = 10616064.

The previous prime is 21232121. The next prime is 21232157. The reversal of 21232144 is 44123212.

It can be written as a sum of positive squares in only one way, i.e., 11696400 + 9535744 = 3420^2 + 3088^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 663489 + ... + 663520.

It is an arithmetic number, because the mean of its divisors is an integer number (4113731).

Almost surely, 2^21232144 is an apocalyptic number.

It is an amenable number.

21232144 is a deficient number, since it is larger than the sum of its proper divisors (19905166).

21232144 is a wasteful number, since it uses less digits than its factorization.

21232144 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1327017 (or 1327011 counting only the distinct ones).

The product of its digits is 384, while the sum is 19.

The square root of 21232144 is about 4607.8350664927. The cubic root of 21232144 is about 276.9053098129.

Adding to 21232144 its reverse (44123212), we get a palindrome (65355356).

The spelling of 21232144 in words is "twenty-one million, two hundred thirty-two thousand, one hundred forty-four".