21143315 has 12 divisors (see below), whose sum is σ = 25987104. Its totient is φ = 16514064.

The previous prime is 21143293. The next prime is 21143327. The reversal of 21143315 is 51334112.

It is not a de Polignac number, because 21143315 - 2⁶ = 21143251 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 8102 + ... + 10388.

It is an arithmetic number, because the mean of its divisors is an integer number (2165592).

Almost surely, 2^21143315 is an apocalyptic number.

21143315 is a deficient number, since it is larger than the sum of its proper divisors (4843789).

21143315 is an equidigital number, since it uses as much as digits as its factorization.

21143315 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2378 (or 2335 counting only the distinct ones).

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

The square root of 21143315 is about 4598.1860553918. The cubic root of 21143315 is about 276.5186067679.

Adding to 21143315 its reverse (51334112), we get a palindrome (72477427).

The spelling of 21143315 in words is "twenty-one million, one hundred forty-three thousand, three hundred fifteen".