21680248 has 16 divisors (see below), whose sum is σ = 40720680. Its totient is φ = 10821408.

The previous prime is 21680231. The next prime is 21680249. The reversal of 21680248 is 84208612.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21680249) 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, 3415 + ... + 7417.

Almost surely, 2^21680248 is an apocalyptic number.

It is an amenable number.

21680248 is a deficient number, since it is larger than the sum of its proper divisors (19040432).

21680248 is a wasteful number, since it uses less digits than its factorization.

21680248 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4686 (or 4682 counting only the distinct ones).

The product of its (nonzero) digits is 6144, while the sum is 31.

The square root of 21680248 is about 4656.2053219333. The cubic root of 21680248 is about 278.8397910309.

The spelling of 21680248 in words is "twenty-one million, six hundred eighty thousand, two hundred forty-eight".