21142315 has 8 divisors (see below), whose sum is σ = 25452720. Its totient is φ = 16859232.

The previous prime is 21142291. The next prime is 21142343. The reversal of 21142315 is 51324112.

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 21142315 - 2⁹ = 21141803 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21142292 and 21142301.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5085 + ... + 8254.

It is an arithmetic number, because the mean of its divisors is an integer number (3181590).

Almost surely, 2^21142315 is an apocalyptic number.

21142315 is a deficient number, since it is larger than the sum of its proper divisors (4310405).

21142315 is a wasteful number, since it uses less digits than its factorization.

21142315 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13661.

The product of its digits is 240, while the sum is 19.

The square root of 21142315 is about 4598.0773155744. The cubic root of 21142315 is about 276.5142472660.

Adding to 21142315 its reverse (51324112), we get a palindrome (72466427).

The spelling of 21142315 in words is "twenty-one million, one hundred forty-two thousand, three hundred fifteen".