21288752 has 10 divisors (see below), whose sum is σ = 41246988. Its totient is φ = 10644368.

The previous prime is 21288749. The next prime is 21288763. The reversal of 21288752 is 25788212.

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, 665258 + ... + 665289.

Almost surely, 2^21288752 is an apocalyptic number.

It is an amenable number.

21288752 is a deficient number, since it is larger than the sum of its proper divisors (19958236).

21288752 is a wasteful number, since it uses less digits than its factorization.

21288752 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1330555 (or 1330549 counting only the distinct ones).

The product of its digits is 17920, while the sum is 35.

The square root of 21288752 is about 4613.9735586585. The cubic root of 21288752 is about 277.1511814453.

The spelling of 21288752 in words is "twenty-one million, two hundred eighty-eight thousand, seven hundred fifty-two".