21045331 has 8 divisors (see below), whose sum is σ = 22625280. Its totient is φ = 19512648.

The previous prime is 21045319. The next prime is 21045377. The reversal of 21045331 is 13354012.

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 21045331 - 2¹³ = 21037139 is a prime.

It is a super-2 number, since 2×21045331² = 885811913799122, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (19).

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21045299 and 21045308.

It is not an unprimeable number, because it can be changed into a prime (21045301) 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, 10891 + ... + 12676.

It is an arithmetic number, because the mean of its divisors is an integer number (2828160).

Almost surely, 2^21045331 is an apocalyptic number.

21045331 is a deficient number, since it is larger than the sum of its proper divisors (1579949).

21045331 is a wasteful number, since it uses less digits than its factorization.

21045331 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23633.

The product of its (nonzero) digits is 360, while the sum is 19.

The square root of 21045331 is about 4587.5190462820. The cubic root of 21045331 is about 276.0907905120.

Adding to 21045331 its reverse (13354012), we get a palindrome (34399343).

The spelling of 21045331 in words is "twenty-one million, forty-five thousand, three hundred thirty-one".