11811318421 has 4 divisors (see below), whose sum is σ = 13498649632. Its totient is φ = 10123987212.

The previous prime is 11811318419. The next prime is 11811318439. The reversal of 11811318421 is 12481311811.

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.

It is a cyclic number.

It is not a de Polignac number, because 11811318421 - 2¹ = 11811318419 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 (11811318481) 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, 843665595 + ... + 843665608.

It is an arithmetic number, because the mean of its divisors is an integer number (3374662408).

Almost surely, 2^11811318421 is an apocalyptic number.

It is an amenable number.

11811318421 is a deficient number, since it is larger than the sum of its proper divisors (1687331211).

11811318421 is an equidigital number, since it uses as much as digits as its factorization.

11811318421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1687331210.

The product of its digits is 1536, while the sum is 31.

The spelling of 11811318421 in words is "eleven billion, eight hundred eleven million, three hundred eighteen thousand, four hundred twenty-one".