11111533440421 has 2 divisors, whose sum is σ = 11111533440422. Its totient is φ = 11111533440420.

The previous prime is 11111533440407. The next prime is 11111533440437. The reversal of 11111533440421 is 12404433511111.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 7941659429025 + 3169874011396 = 2818095^2 + 1780414^2 .

It is an emirp because it is prime and its reverse (12404433511111) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 11111533440421 - 2⁴¹ = 8912510184869 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (11111533440121) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5555766720210 + 5555766720211.

It is an arithmetic number, because the mean of its divisors is an integer number (5555766720211).

Almost surely, 2^{11111533440421} is an apocalyptic number.

It is an amenable number.

11111533440421 is a deficient number, since it is larger than the sum of its proper divisors (1).

11111533440421 is an equidigital number, since it uses as much as digits as its factorization.

11111533440421 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5760, while the sum is 31.

Adding to 11111533440421 its reverse (12404433511111), we get a palindrome (23515966951532).

The spelling of 11111533440421 in words is "eleven trillion, one hundred eleven billion, five hundred thirty-three million, four hundred forty thousand, four hundred twenty-one".