21165233315 has 8 divisors (see below), whose sum is σ = 25488667008. Its totient is φ = 16871928640.

The previous prime is 21165233269. The next prime is 21165233317. The reversal of 21165233315 is 51333256112.

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

It is not a de Polignac number, because 21165233315 - 2⁸ = 21165233059 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21165233317) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7530707 + ... + 7533516.

It is an arithmetic number, because the mean of its divisors is an integer number (3186083376).

Almost surely, 2^21165233315 is an apocalyptic number.

21165233315 is a deficient number, since it is larger than the sum of its proper divisors (4323433693).

21165233315 is a wasteful number, since it uses less digits than its factorization.

21165233315 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15064509.

The product of its digits is 16200, while the sum is 32.

Adding to 21165233315 its reverse (51333256112), we get a palindrome (72498489427).

The spelling of 21165233315 in words is "twenty-one billion, one hundred sixty-five million, two hundred thirty-three thousand, three hundred fifteen".