21417315 has 8 divisors (see below), whose sum is σ = 34267728. Its totient is φ = 11422560.

The previous prime is 21417307. The next prime is 21417317. The reversal of 21417315 is 51371412.

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

It is not a de Polignac number, because 21417315 - 2³ = 21417307 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21417317) 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, 713896 + ... + 713925.

It is an arithmetic number, because the mean of its divisors is an integer number (4283466).

Almost surely, 2^21417315 is an apocalyptic number.

21417315 is a deficient number, since it is larger than the sum of its proper divisors (12850413).

21417315 is a wasteful number, since it uses less digits than its factorization.

21417315 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1427829.

The product of its digits is 840, while the sum is 24.

The square root of 21417315 is about 4627.8845059055. The cubic root of 21417315 is about 277.7079684426.

Adding to 21417315 its reverse (51371412), we get a palindrome (72788727).

The spelling of 21417315 in words is "twenty-one million, four hundred seventeen thousand, three hundred fifteen".