11311221421 has 2 divisors, whose sum is σ = 11311221422. Its totient is φ = 11311221420.

The previous prime is 11311221413. The next prime is 11311221443. The reversal of 11311221421 is 12412211311.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 9193933225 + 2117288196 = 95885^2 + 46014^2 .

It is a cyclic number.

It is not a de Polignac number, because 11311221421 - 2³ = 11311221413 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (11311221461) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5655610710 + 5655610711.

It is an arithmetic number, because the mean of its divisors is an integer number (5655610711).

Almost surely, 2^11311221421 is an apocalyptic number.

It is an amenable number.

11311221421 is a deficient number, since it is larger than the sum of its proper divisors (1).

11311221421 is an equidigital number, since it uses as much as digits as its factorization.

11311221421 is an evil number, because the sum of its binary digits is even.

The product of its digits is 96, while the sum is 19.

Adding to 11311221421 its reverse (12412211311), we get a palindrome (23723432732).

The spelling of 11311221421 in words is "eleven billion, three hundred eleven million, two hundred twenty-one thousand, four hundred twenty-one".