11551321551 has 64 divisors (see below), whose sum is σ = 20438424576. Its totient is φ = 5618073600.

The previous prime is 11551321511. The next prime is 11551321603. The reversal of 11551321551 is 15512315511.

11551321551 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 11551321551 - 2⁷ = 11551321423 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11551321511) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 750291 + ... + 765531.

It is an arithmetic number, because the mean of its divisors is an integer number (319350384).

Almost surely, 2^11551321551 is an apocalyptic number.

11551321551 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

11551321551 is a deficient number, since it is larger than the sum of its proper divisors (8887103025).

11551321551 is a wasteful number, since it uses less digits than its factorization.

11551321551 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15472.

The product of its digits is 3750, while the sum is 30.

The spelling of 11551321551 in words is "eleven billion, five hundred fifty-one million, three hundred twenty-one thousand, five hundred fifty-one".