21100311131 has 2 divisors, whose sum is σ = 21100311132. Its totient is φ = 21100311130.

The previous prime is 21100311109. The next prime is 21100311137. The reversal of 21100311131 is 13111300112.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21100311131 - 2¹⁸ = 21100048987 is a prime.

It is a super-2 number, since 2×21100311131² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (21100311137) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10550155565 + 10550155566.

It is an arithmetic number, because the mean of its divisors is an integer number (10550155566).

Almost surely, 2^21100311131 is an apocalyptic number.

21100311131 is a deficient number, since it is larger than the sum of its proper divisors (1).

21100311131 is an equidigital number, since it uses as much as digits as its factorization.

21100311131 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 18, while the sum is 14.

Adding to 21100311131 its reverse (13111300112), we get a palindrome (34211611243).

The spelling of 21100311131 in words is "twenty-one billion, one hundred million, three hundred eleven thousand, one hundred thirty-one".