21213311331181 has 2 divisors, whose sum is σ = 21213311331182. Its totient is φ = 21213311331180.

The previous prime is 21213311331137. The next prime is 21213311331217. The reversal of 21213311331181 is 18113311331212.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 13401705575556 + 7811605755625 = 3660834^2 + 2794925^2 .

It is a cyclic number.

It is not a de Polignac number, because 21213311331181 - 2³³ = 21204721396589 is a prime.

It is a super-2 number, since 2×21213311331181² (a number of 27 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21213311331131) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10606655665590 + 10606655665591.

It is an arithmetic number, because the mean of its divisors is an integer number (10606655665591).

Almost surely, 2^{21213311331181} is an apocalyptic number.

It is an amenable number.

21213311331181 is a deficient number, since it is larger than the sum of its proper divisors (1).

21213311331181 is an equidigital number, since it uses as much as digits as its factorization.

21213311331181 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2592, while the sum is 31.

Adding to 21213311331181 its sum of digits (31), we get a palindrome (21213311331212).

Adding to 21213311331181 its reverse (18113311331212), we get a palindrome (39326622662393).

The spelling of 21213311331181 in words is "twenty-one trillion, two hundred thirteen billion, three hundred eleven million, three hundred thirty-one thousand, one hundred eighty-one".