11555401421 has 2 divisors, whose sum is σ = 11555401422. Its totient is φ = 11555401420.

The previous prime is 11555401397. The next prime is 11555401427. The reversal of 11555401421 is 12410455511.

11555401421 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 10430536900 + 1124864521 = 102130^2 + 33539^2 .

It is a cyclic number.

It is not a de Polignac number, because 11555401421 - 2²² = 11551207117 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (11555401427) 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 as a sum of consecutive naturals, namely, 5777700710 + 5777700711.

It is an arithmetic number, because the mean of its divisors is an integer number (5777700711).

Almost surely, 2^11555401421 is an apocalyptic number.

It is an amenable number.

11555401421 is a deficient number, since it is larger than the sum of its proper divisors (1).

11555401421 is an equidigital number, since it uses as much as digits as its factorization.

11555401421 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 4000, while the sum is 29.

Adding to 11555401421 its reverse (12410455511), we get a palindrome (23965856932).

The spelling of 11555401421 in words is "eleven billion, five hundred fifty-five million, four hundred one thousand, four hundred twenty-one".