11506561511 has 4 divisors (see below), whose sum is σ = 11509320432. Its totient is φ = 11503802592.

The previous prime is 11506561477. The next prime is 11506561523. The reversal of 11506561511 is 11516560511.

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 11506561511 - 2¹⁰ = 11506560487 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 (11506560511) 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 3 ways as a sum of consecutive naturals, for example, 1373195 + ... + 1381548.

It is an arithmetic number, because the mean of its divisors is an integer number (2877330108).

Almost surely, 2^11506561511 is an apocalyptic number.

11506561511 is a deficient number, since it is larger than the sum of its proper divisors (2758921).

11506561511 is an equidigital number, since it uses as much as digits as its factorization.

11506561511 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2758920.

The product of its (nonzero) digits is 4500, while the sum is 32.

The spelling of 11506561511 in words is "eleven billion, five hundred six million, five hundred sixty-one thousand, five hundred eleven".