21680496 has 30 divisors (see below), whose sum is σ = 60675680. Its totient is φ = 7226784.

The previous prime is 21680479. The next prime is 21680497. The reversal of 21680496 is 69408612.

21680496 is a `hidden beast` number, since 2 + 168 + 0 + 496 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a self number, because there is not a number n which added to its sum of digits gives 21680496.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21680497) 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 5 ways as a sum of consecutive naturals, for example, 75136 + ... + 75423.

Almost surely, 2^21680496 is an apocalyptic number.

It is an amenable number.

21680496 is an abundant number, since it is smaller than the sum of its proper divisors (38995184).

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

21680496 is a wasteful number, since it uses less digits than its factorization.

21680496 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 150573 (or 150564 counting only the distinct ones).

The product of its (nonzero) digits is 20736, while the sum is 36.

The square root of 21680496 is about 4656.2319529852. The cubic root of 21680496 is about 278.8408542414.

The spelling of 21680496 in words is "twenty-one million, six hundred eighty thousand, four hundred ninety-six".