21996065 has 32 divisors (see below), whose sum is σ = 33626880. Its totient is φ = 13434624.

The previous prime is 21996041. The next prime is 21996077. The reversal of 21996065 is 56069912.

It is not a de Polignac number, because 21996065 - 2⁶ = 21996001 is a prime.

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 31 ways as a sum of consecutive naturals, for example, 12362 + ... + 14028.

It is an arithmetic number, because the mean of its divisors is an integer number (1050840).

Almost surely, 2^21996065 is an apocalyptic number.

It is an amenable number.

21996065 is a deficient number, since it is larger than the sum of its proper divisors (11630815).

21996065 is a wasteful number, since it uses less digits than its factorization.

21996065 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1721.

The product of its (nonzero) digits is 29160, while the sum is 38.

The square root of 21996065 is about 4689.9962686552. The cubic root of 21996065 is about 280.1872259713.

The spelling of 21996065 in words is "twenty-one million, nine hundred ninety-six thousand, sixty-five".