21371315 has 16 divisors (see below), whose sum is σ = 29529792. Its totient is φ = 14544384.

The previous prime is 21371299. The next prime is 21371341. The reversal of 21371315 is 51317312.

It is a cyclic number.

It is not a de Polignac number, because 21371315 - 2⁴ = 21371299 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2567 + ... + 7023.

It is an arithmetic number, because the mean of its divisors is an integer number (1845612).

Almost surely, 2^21371315 is an apocalyptic number.

21371315 is a deficient number, since it is larger than the sum of its proper divisors (8158477).

21371315 is a wasteful number, since it uses less digits than its factorization.

21371315 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4606.

The product of its digits is 630, while the sum is 23.

The square root of 21371315 is about 4622.9119610912. The cubic root of 21371315 is about 277.5090060113.

Adding to 21371315 its reverse (51317312), we get a palindrome (72688627).

The spelling of 21371315 in words is "twenty-one million, three hundred seventy-one thousand, three hundred fifteen".