21026065 has 8 divisors (see below), whose sum is σ = 26559360. Its totient is φ = 15935472.

The previous prime is 21026063. The next prime is 21026069. The reversal of 21026065 is 56062012.

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 21026065 - 2¹ = 21026063 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21026063) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 110569 + ... + 110758.

It is an arithmetic number, because the mean of its divisors is an integer number (3319920).

Almost surely, 2^21026065 is an apocalyptic number.

It is an amenable number.

21026065 is a deficient number, since it is larger than the sum of its proper divisors (5533295).

21026065 is a wasteful number, since it uses less digits than its factorization.

21026065 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 221351.

The product of its (nonzero) digits is 720, while the sum is 22.

The square root of 21026065 is about 4585.4187376945. The cubic root of 21026065 is about 276.0065154592.

Adding to 21026065 its reverse (56062012), we get a palindrome (77088077).

The spelling of 21026065 in words is "twenty-one million, twenty-six thousand, sixty-five".