21134515 has 4 divisors (see below), whose sum is σ = 25361424. Its totient is φ = 16907608.

The previous prime is 21134513. The next prime is 21134521. The reversal of 21134515 is 51543112.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21134515 - 2¹ = 21134513 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21134513) 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 3 ways as a sum of consecutive naturals, for example, 2113447 + ... + 2113456.

It is an arithmetic number, because the mean of its divisors is an integer number (6340356).

Almost surely, 2^21134515 is an apocalyptic number.

21134515 is a deficient number, since it is larger than the sum of its proper divisors (4226909).

21134515 is an equidigital number, since it uses as much as digits as its factorization.

21134515 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4226908.

The product of its digits is 600, while the sum is 22.

The square root of 21134515 is about 4597.2290567254. The cubic root of 21134515 is about 276.4802384324.

Adding to 21134515 its reverse (51543112), we get a palindrome (72677627).

The spelling of 21134515 in words is "twenty-one million, one hundred thirty-four thousand, five hundred fifteen".