21247608 has 32 divisors (see below), whose sum is σ = 53544960. Its totient is φ = 7025760.

The previous prime is 21247591. The next prime is 21247613. The reversal of 21247608 is 80674212.

It is a congruent number.

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, 438 + ... + 6533.

It is an arithmetic number, because the mean of its divisors is an integer number (1673280).

Almost surely, 2^21247608 is an apocalyptic number.

It is an amenable number.

21247608 is an abundant number, since it is smaller than the sum of its proper divisors (32297352).

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

21247608 is a wasteful number, since it uses less digits than its factorization.

21247608 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7107 (or 7103 counting only the distinct ones).

The product of its (nonzero) digits is 5376, while the sum is 30.

The square root of 21247608 is about 4609.5127725173. The cubic root of 21247608 is about 276.9725196144.

The spelling of 21247608 in words is "twenty-one million, two hundred forty-seven thousand, six hundred eight".