21041515 has 16 divisors (see below), whose sum is σ = 27703296. Its totient is φ = 15215200.

The previous prime is 21041513. The next prime is 21041519. The reversal of 21041515 is 51514012.

It is not a de Polignac number, because 21041515 - 2¹ = 21041513 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21041492 and 21041501.

It is not an unprimeable number, because it can be changed into a prime (21041513) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 9504 + ... + 11506.

It is an arithmetic number, because the mean of its divisors is an integer number (1731456).

Almost surely, 2^21041515 is an apocalyptic number.

21041515 is a deficient number, since it is larger than the sum of its proper divisors (6661781).

21041515 is a wasteful number, since it uses less digits than its factorization.

21041515 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2210.

The product of its (nonzero) digits is 200, while the sum is 19.

The square root of 21041515 is about 4587.1031163470. The cubic root of 21041515 is about 276.0741023110.

Adding to 21041515 its reverse (51514012), we get a palindrome (72555527).

The spelling of 21041515 in words is "twenty-one million, forty-one thousand, five hundred fifteen".