21111144277 has 2 divisors, whose sum is σ = 21111144278. Its totient is φ = 21111144276.

The previous prime is 21111144253. The next prime is 21111144337. The reversal of 21111144277 is 77244111112.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20655150961 + 455993316 = 143719^2 + 21354^2 .

It is a cyclic number.

It is not a de Polignac number, because 21111144277 - 2¹¹ = 21111142229 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21111144217) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10555572138 + 10555572139.

It is an arithmetic number, because the mean of its divisors is an integer number (10555572139).

Almost surely, 2^21111144277 is an apocalyptic number.

It is an amenable number.

21111144277 is a deficient number, since it is larger than the sum of its proper divisors (1).

21111144277 is an equidigital number, since it uses as much as digits as its factorization.

21111144277 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3136, while the sum is 31.

Adding to 21111144277 its reverse (77244111112), we get a palindrome (98355255389).

The spelling of 21111144277 in words is "twenty-one billion, one hundred eleven million, one hundred forty-four thousand, two hundred seventy-seven".