21081484 has 12 divisors (see below), whose sum is σ = 36978984. Its totient is φ = 10516064.

The previous prime is 21081443. The next prime is 21081491. The reversal of 21081484 is 48418012.

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 in 3 ways as a sum of consecutive naturals, for example, 4177 + ... + 7720.

It is an arithmetic number, because the mean of its divisors is an integer number (3081582).

Almost surely, 2^21081484 is an apocalyptic number.

It is an amenable number.

21081484 is a deficient number, since it is larger than the sum of its proper divisors (15897500).

21081484 is a wasteful number, since it uses less digits than its factorization.

21081484 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12344 (or 12342 counting only the distinct ones).

The product of its (nonzero) digits is 2048, while the sum is 28.

The square root of 21081484 is about 4591.4577205938. The cubic root of 21081484 is about 276.2487954740.

Adding to 21081484 its reverse (48418012), we get a palindrome (69499496).

The spelling of 21081484 in words is "twenty-one million, eighty-one thousand, four hundred eighty-four".