21084668 has 24 divisors (see below), whose sum is σ = 40449024. Its totient is φ = 9537200.

The previous prime is 21084649. The next prime is 21084673. The reversal of 21084668 is 86648012.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8933 + ... + 11043.

It is an arithmetic number, because the mean of its divisors is an integer number (1685376).

Almost surely, 2^21084668 is an apocalyptic number.

It is an amenable number.

21084668 is a deficient number, since it is larger than the sum of its proper divisors (19364356).

21084668 is a wasteful number, since it uses less digits than its factorization.

21084668 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2353 (or 2351 counting only the distinct ones).

The product of its (nonzero) digits is 18432, while the sum is 35.

The square root of 21084668 is about 4591.8044383445. The cubic root of 21084668 is about 276.2627023363.

It can be divided in two parts, 2108 and 4668, that added together give a palindrome (6776).

The spelling of 21084668 in words is "twenty-one million, eighty-four thousand, six hundred sixty-eight".