21045365 has 8 divisors (see below), whose sum is σ = 27550368. Its totient is φ = 15305680.

The previous prime is 21045319. The next prime is 21045377. The reversal of 21045365 is 56354012.

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

It is not a de Polignac number, because 21045365 - 2⁶ = 21045301 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 191267 + ... + 191376.

It is an arithmetic number, because the mean of its divisors is an integer number (3443796).

Almost surely, 2^21045365 is an apocalyptic number.

It is an amenable number.

21045365 is a deficient number, since it is larger than the sum of its proper divisors (6505003).

21045365 is a wasteful number, since it uses less digits than its factorization.

21045365 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 382659.

The product of its (nonzero) digits is 3600, while the sum is 26.

The square root of 21045365 is about 4587.5227519872. The cubic root of 21045365 is about 276.0909391923.

Adding to 21045365 its reverse (56354012), we get a palindrome (77399377).

The spelling of 21045365 in words is "twenty-one million, forty-five thousand, three hundred sixty-five".