21131324581811 has 2 divisors, whose sum is σ = 21131324581812. Its totient is φ = 21131324581810.

The previous prime is 21131324581733. The next prime is 21131324581837. The reversal of 21131324581811 is 11818542313112.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21131324581811 - 2²⁶ = 21131257472947 is a prime.

It is not a weakly prime, because it can be changed into another prime (21131324581891) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10565662290905 + 10565662290906.

It is an arithmetic number, because the mean of its divisors is an integer number (10565662290906).

Almost surely, 2^{21131324581811} is an apocalyptic number.

21131324581811 is a deficient number, since it is larger than the sum of its proper divisors (1).

21131324581811 is an equidigital number, since it uses as much as digits as its factorization.

21131324581811 is an evil number, because the sum of its binary digits is even.

The product of its digits is 46080, while the sum is 41.

Adding to 21131324581811 its reverse (11818542313112), we get a palindrome (32949866894923).

The spelling of 21131324581811 in words is "twenty-one trillion, one hundred thirty-one billion, three hundred twenty-four million, five hundred eighty-one thousand, eight hundred eleven".