21288648 has 32 divisors (see below), whose sum is σ = 53344800. Its totient is φ = 7079808.

The previous prime is 21288637. The next prime is 21288671. The reversal of 21288648 is 84688212.

It is a nude number because it is divisible by every one of its digits.

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 7 ways as a sum of consecutive naturals, for example, 14140 + ... + 15572.

It is an arithmetic number, because the mean of its divisors is an integer number (1667025).

Almost surely, 2^21288648 is an apocalyptic number.

It is an amenable number.

21288648 is an abundant number, since it is smaller than the sum of its proper divisors (32056152).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21288648 is a wasteful number, since it uses less digits than its factorization.

21288648 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2061 (or 2057 counting only the distinct ones).

The product of its digits is 49152, while the sum is 39.

The square root of 21288648 is about 4613.9622885325. The cubic root of 21288648 is about 277.1507301308.

The spelling of 21288648 in words is "twenty-one million, two hundred eighty-eight thousand, six hundred forty-eight".