21668046 has 16 divisors (see below), whose sum is σ = 44830800. Its totient is φ = 6973568.

The previous prime is 21668033. The next prime is 21668099. The reversal of 21668046 is 64086612.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 21667998 and 21668016.

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, 62091 + ... + 62438.

It is an arithmetic number, because the mean of its divisors is an integer number (2801925).

Almost surely, 2^21668046 is an apocalyptic number.

21668046 is an abundant number, since it is smaller than the sum of its proper divisors (23162754).

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

21668046 is a wasteful number, since it uses less digits than its factorization.

21668046 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 124563.

The product of its (nonzero) digits is 13824, while the sum is 33.

The square root of 21668046 is about 4654.8948430657. The cubic root of 21668046 is about 278.7874693410.

The spelling of 21668046 in words is "twenty-one million, six hundred sixty-eight thousand, forty-six".