21045369 has 16 divisors (see below), whose sum is σ = 29641280. Its totient is φ = 13245120.

The previous prime is 21045319. The next prime is 21045377. The reversal of 21045369 is 96354012.

It is not a de Polignac number, because 21045369 - 2²⁰ = 19996793 is a prime.

It is a super-2 number, since 2×21045369² = 885815112692322, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21045319) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 23559 + ... + 24435.

It is an arithmetic number, because the mean of its divisors is an integer number (1852580).

Almost surely, 2^21045369 is an apocalyptic number.

It is an amenable number.

21045369 is a deficient number, since it is larger than the sum of its proper divisors (8595911).

21045369 is a wasteful number, since it uses less digits than its factorization.

21045369 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1320.

The product of its (nonzero) digits is 6480, while the sum is 30.

The square root of 21045369 is about 4587.5231879523. The cubic root of 21045369 is about 276.0909566841.

The spelling of 21045369 in words is "twenty-one million, forty-five thousand, three hundred sixty-nine".