21533313115 has 16 divisors (see below), whose sum is σ = 27081230400. Its totient is φ = 16405690752.

The previous prime is 21533313107. The next prime is 21533313163. The reversal of 21533313115 is 51131333512.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 21533313115 - 2³ = 21533313107 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 382500 + ... + 435169.

It is an arithmetic number, because the mean of its divisors is an integer number (1692576900).

Almost surely, 2^21533313115 is an apocalyptic number.

21533313115 is a deficient number, since it is larger than the sum of its proper divisors (5547917285).

21533313115 is a wasteful number, since it uses less digits than its factorization.

21533313115 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 817926.

The product of its digits is 4050, while the sum is 28.

Adding to 21533313115 its reverse (51131333512), we get a palindrome (72664646627).

The spelling of 21533313115 in words is "twenty-one billion, five hundred thirty-three million, three hundred thirteen thousand, one hundred fifteen".