21045315 has 8 divisors (see below), whose sum is σ = 33672528. Its totient is φ = 11224160.

The previous prime is 21045301. The next prime is 21045317. The reversal of 21045315 is 51354012.

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

It is not a de Polignac number, because 21045315 - 2¹⁰ = 21044291 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21045291 and 21045300.

It is not an unprimeable number, because it can be changed into a prime (21045317) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 701496 + ... + 701525.

It is an arithmetic number, because the mean of its divisors is an integer number (4209066).

Almost surely, 2^21045315 is an apocalyptic number.

21045315 is a deficient number, since it is larger than the sum of its proper divisors (12627213).

21045315 is a wasteful number, since it uses less digits than its factorization.

21045315 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1403029.

The product of its (nonzero) digits is 600, while the sum is 21.

The square root of 21045315 is about 4587.5173024197. The cubic root of 21045315 is about 276.0907205447.

Adding to 21045315 its reverse (51354012), we get a palindrome (72399327).

The spelling of 21045315 in words is "twenty-one million, forty-five thousand, three hundred fifteen".