21304043515 has 8 divisors (see below), whose sum is σ = 25983948528. Its totient is φ = 16763837280.

The previous prime is 21304043513. The next prime is 21304043587. The reversal of 21304043515 is 51534040312.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21304043515 - 2¹ = 21304043513 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21304043513) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 34924357 + ... + 34924966.

It is an arithmetic number, because the mean of its divisors is an integer number (3247993566).

Almost surely, 2^21304043515 is an apocalyptic number.

21304043515 is a deficient number, since it is larger than the sum of its proper divisors (4679905013).

21304043515 is an equidigital number, since it uses as much as digits as its factorization.

21304043515 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 69849389.

The product of its (nonzero) digits is 7200, while the sum is 28.

Adding to 21304043515 its reverse (51534040312), we get a palindrome (72838083827).

The spelling of 21304043515 in words is "twenty-one billion, three hundred four million, forty-three thousand, five hundred fifteen".