11388813251521 has 4 divisors (see below), whose sum is σ = 11388823559344. Its totient is φ = 11388802943700.

The previous prime is 11388813251479. The next prime is 11388813251527. The reversal of 11388813251521 is 12515231888311.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-11388813251521 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (11388813251527) 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, 3266115 + ... + 5783176.

It is an arithmetic number, because the mean of its divisors is an integer number (2847205889836).

Almost surely, 2^{11388813251521} is an apocalyptic number.

It is an amenable number.

11388813251521 is a deficient number, since it is larger than the sum of its proper divisors (10307823).

11388813251521 is an equidigital number, since it uses as much as digits as its factorization.

11388813251521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10307822.

The product of its digits is 460800, while the sum is 49.

The spelling of 11388813251521 in words is "eleven trillion, three hundred eighty-eight billion, eight hundred thirteen million, two hundred fifty-one thousand, five hundred twenty-one".