21442315 has 8 divisors (see below), whose sum is σ = 25959168. Its totient is φ = 17001600.

The previous prime is 21442313. The next prime is 21442319. The reversal of 21442315 is 51324412.

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

It is not a de Polignac number, because 21442315 - 2¹ = 21442313 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21442313) 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 7 ways as a sum of consecutive naturals, for example, 18411 + ... + 19540.

It is an arithmetic number, because the mean of its divisors is an integer number (3244896).

Almost surely, 2^21442315 is an apocalyptic number.

21442315 is a deficient number, since it is larger than the sum of its proper divisors (4516853).

21442315 is a wasteful number, since it uses less digits than its factorization.

21442315 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 38069.

The product of its digits is 960, while the sum is 22.

The square root of 21442315 is about 4630.5847362941. The cubic root of 21442315 is about 277.8159807309.

Adding to 21442315 its reverse (51324412), we get a palindrome (72766727).

The spelling of 21442315 in words is "twenty-one million, four hundred forty-two thousand, three hundred fifteen".