11500505551 has 4 divisors (see below), whose sum is σ = 11512350504. Its totient is φ = 11488660600.

The previous prime is 11500505543. The next prime is 11500505677. The reversal of 11500505551 is 15550500511.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 11500505551 - 2³ = 11500505543 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11500502551) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5921020 + ... + 5922961.

It is an arithmetic number, because the mean of its divisors is an integer number (2878087626).

Almost surely, 2^11500505551 is an apocalyptic number.

11500505551 is a deficient number, since it is larger than the sum of its proper divisors (11844953).

11500505551 is an equidigital number, since it uses as much as digits as its factorization.

11500505551 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11844952.

The product of its (nonzero) digits is 3125, while the sum is 28.

The spelling of 11500505551 in words is "eleven billion, five hundred million, five hundred five thousand, five hundred fifty-one".