21315413 has 8 divisors (see below), whose sum is σ = 24760320. Its totient is φ = 17970480.

The previous prime is 21315391. The next prime is 21315421. The reversal of 21315413 is 31451312.

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

It is a cyclic number.

It is not a de Polignac number, because 21315413 - 2¹⁴ = 21299029 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21315443) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 24533 + ... + 25386.

It is an arithmetic number, because the mean of its divisors is an integer number (3095040).

Almost surely, 2^21315413 is an apocalyptic number.

It is an amenable number.

21315413 is a deficient number, since it is larger than the sum of its proper divisors (3444907).

21315413 is an equidigital number, since it uses as much as digits as its factorization.

21315413 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 49987.

The product of its digits is 360, while the sum is 20.

The square root of 21315413 is about 4616.8618129634. The cubic root of 21315413 is about 277.2668300783.

Adding to 21315413 its reverse (31451312), we get a palindrome (52766725).

The spelling of 21315413 in words is "twenty-one million, three hundred fifteen thousand, four hundred thirteen".