21065297 has 8 divisors (see below), whose sum is σ = 23081760. Its totient is φ = 19065760.

The previous prime is 21065287. The next prime is 21065333. The reversal of 21065297 is 79256012.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21065297 - 2⁸ = 21065041 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21065207) 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 in 7 ways as a sum of consecutive naturals, for example, 1547 + ... + 6672.

It is an arithmetic number, because the mean of its divisors is an integer number (2885220).

Almost surely, 2^21065297 is an apocalyptic number.

It is an amenable number.

21065297 is a deficient number, since it is larger than the sum of its proper divisors (2016463).

21065297 is a wasteful number, since it uses less digits than its factorization.

21065297 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8463.

The product of its (nonzero) digits is 7560, while the sum is 32.

The square root of 21065297 is about 4589.6946521528. The cubic root of 21065297 is about 276.1780733144.

The spelling of 21065297 in words is "twenty-one million, sixty-five thousand, two hundred ninety-seven".