21084716 has 6 divisors (see below), whose sum is σ = 36898260. Its totient is φ = 10542356.

The previous prime is 21084697. The next prime is 21084719. The reversal of 21084716 is 61748012.

It is not an unprimeable number, because it can be changed into a prime (21084719) 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 as a sum of consecutive naturals, namely, 2635586 + ... + 2635593.

It is an arithmetic number, because the mean of its divisors is an integer number (6149710).

Almost surely, 2^21084716 is an apocalyptic number.

It is an amenable number.

21084716 is a deficient number, since it is larger than the sum of its proper divisors (15813544).

21084716 is a wasteful number, since it uses less digits than its factorization.

21084716 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5271183 (or 5271181 counting only the distinct ones).

The product of its (nonzero) digits is 2688, while the sum is 29.

The square root of 21084716 is about 4591.8096650449. The cubic root of 21084716 is about 276.2629119768.

The spelling of 21084716 in words is "twenty-one million, eighty-four thousand, seven hundred sixteen".