11115513521 has 16 divisors (see below), whose sum is σ = 12833353728. Its totient is φ = 9430246800.

The previous prime is 11115513517. The next prime is 11115513527. The reversal of 11115513521 is 12531551111.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 11115513521 - 2² = 11115513517 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (11115513527) 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, 2529236 + ... + 2533626.

It is an arithmetic number, because the mean of its divisors is an integer number (802084608).

Almost surely, 2^11115513521 is an apocalyptic number.

It is an amenable number.

11115513521 is a deficient number, since it is larger than the sum of its proper divisors (1717840207).

11115513521 is a wasteful number, since it uses less digits than its factorization.

11115513521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8012.

The product of its digits is 750, while the sum is 26.

The spelling of 11115513521 in words is "eleven billion, one hundred fifteen million, five hundred thirteen thousand, five hundred twenty-one".