21144315 has 16 divisors (see below), whose sum is σ = 34657056. Its totient is φ = 11001600.

The previous prime is 21144307. The next prime is 21144323. The reversal of 21144315 is 51344112.

It is an interprime number because it is at equal distance from previous prime (21144307) and next prime (21144323).

It is not a de Polignac number, because 21144315 - 2³ = 21144307 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21144291 and 21144300.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 16576 + ... + 17805.

It is an arithmetic number, because the mean of its divisors is an integer number (2166066).

Almost surely, 2^21144315 is an apocalyptic number.

21144315 is a deficient number, since it is larger than the sum of its proper divisors (13512741).

21144315 is a wasteful number, since it uses less digits than its factorization.

21144315 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 34430.

The product of its digits is 480, while the sum is 21.

The square root of 21144315 is about 4598.2947926378. The cubic root of 21144315 is about 276.5229661323.

Adding to 21144315 its reverse (51344112), we get a palindrome (72488427).

The spelling of 21144315 in words is "twenty-one million, one hundred forty-four thousand, three hundred fifteen".