21471065 has 48 divisors (see below), whose sum is σ = 33882624. Its totient is φ = 12902400.

The previous prime is 21471041. The next prime is 21471067. The reversal of 21471065 is 56017412.

It is not a de Polignac number, because 21471065 - 2⁸ = 21470809 is a prime.

It is a super-2 number, since 2×21471065² = 922013264468450, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21471067) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 83417 + ... + 83673.

It is an arithmetic number, because the mean of its divisors is an integer number (705888).

Almost surely, 2^21471065 is an apocalyptic number.

It is an amenable number.

21471065 is a deficient number, since it is larger than the sum of its proper divisors (12411559).

21471065 is a wasteful number, since it uses less digits than its factorization.

21471065 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 318 (or 311 counting only the distinct ones).

The product of its (nonzero) digits is 1680, while the sum is 26.

The square root of 21471065 is about 4633.6880559658. The cubic root of 21471065 is about 277.9400911225.

Adding to 21471065 its reverse (56017412), we get a palindrome (77488477).

The spelling of 21471065 in words is "twenty-one million, four hundred seventy-one thousand, sixty-five".