21065316 has 12 divisors (see below), whose sum is σ = 49152432. Its totient is φ = 7021768.

The previous prime is 21065287. The next prime is 21065333. The reversal of 21065316 is 61356012.

It is a tau number, because it is divible by the number of its divisors (12).

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 3 ways as a sum of consecutive naturals, for example, 877710 + ... + 877733.

It is an arithmetic number, because the mean of its divisors is an integer number (4096036).

Almost surely, 2^21065316 is an apocalyptic number.

It is an amenable number.

21065316 is an abundant number, since it is smaller than the sum of its proper divisors (28087116).

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

21065316 is a wasteful number, since it uses less digits than its factorization.

21065316 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1755450 (or 1755448 counting only the distinct ones).

The product of its (nonzero) digits is 1080, while the sum is 24.

The square root of 21065316 is about 4589.6967220068. The cubic root of 21065316 is about 276.1781563480.

The spelling of 21065316 in words is "twenty-one million, sixty-five thousand, three hundred sixteen".