21027288 has 16 divisors (see below), whose sum is σ = 52568280. Its totient is φ = 7009088.

The previous prime is 21027287. The next prime is 21027323. The reversal of 21027288 is 88272012.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21027287) by changing a digit.

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, 438045 + ... + 438092.

Almost surely, 2^21027288 is an apocalyptic number.

It is an amenable number.

21027288 is an abundant number, since it is smaller than the sum of its proper divisors (31540992).

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

21027288 is a wasteful number, since it uses less digits than its factorization.

21027288 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 876146 (or 876142 counting only the distinct ones).

The product of its (nonzero) digits is 3584, while the sum is 30.

The square root of 21027288 is about 4585.5520932599. The cubic root of 21027288 is about 276.0118667446.

The spelling of 21027288 in words is "twenty-one million, twenty-seven thousand, two hundred eighty-eight".