21069265 has 24 divisors (see below), whose sum is σ = 30697920. Its totient is φ = 13815648.

The previous prime is 21069253. The next prime is 21069287. The reversal of 21069265 is 56296012.

It is not a de Polignac number, because 21069265 - 2¹⁷ = 20938193 is a prime.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 3766 + ... + 7504.

It is an arithmetic number, because the mean of its divisors is an integer number (1279080).

Almost surely, 2^21069265 is an apocalyptic number.

It is an amenable number.

21069265 is a deficient number, since it is larger than the sum of its proper divisors (9628655).

21069265 is a wasteful number, since it uses less digits than its factorization.

21069265 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3781 (or 3774 counting only the distinct ones).

The product of its (nonzero) digits is 6480, while the sum is 31.

The square root of 21069265 is about 4590.1269045638. The cubic root of 21069265 is about 276.1954131410.

The spelling of 21069265 in words is "twenty-one million, sixty-nine thousand, two hundred sixty-five".