21444715 has 12 divisors (see below), whose sum is σ = 26596512. Its totient is φ = 16598640.

The previous prime is 21444713. The next prime is 21444721. The reversal of 21444715 is 51744412.

It is not a de Polignac number, because 21444715 - 2¹ = 21444713 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21444713) by changing a digit.

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 11 ways as a sum of consecutive naturals, for example, 2574 + ... + 7036.

It is an arithmetic number, because the mean of its divisors is an integer number (2216376).

Almost surely, 2^21444715 is an apocalyptic number.

21444715 is a deficient number, since it is larger than the sum of its proper divisors (5151797).

21444715 is an equidigital number, since it uses as much as digits as its factorization.

21444715 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4530 (or 4499 counting only the distinct ones).

The product of its digits is 4480, while the sum is 28.

The square root of 21444715 is about 4630.8438755803. The cubic root of 21444715 is about 277.8263454929.

It can be divided in two parts, 2144 and 4715, that added together give a cube (6859 = 19³).

The spelling of 21444715 in words is "twenty-one million, four hundred forty-four thousand, seven hundred fifteen".