20211110261 has 2 divisors, whose sum is σ = 20211110262. Its totient is φ = 20211110260.

The previous prime is 20211110239. The next prime is 20211110357. The reversal of 20211110261 is 16201111202.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19179480100 + 1031630161 = 138490^2 + 32119^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20211110261 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20211110461) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10105555130 + 10105555131.

It is an arithmetic number, because the mean of its divisors is an integer number (10105555131).

Almost surely, 2^20211110261 is an apocalyptic number.

It is an amenable number.

20211110261 is a deficient number, since it is larger than the sum of its proper divisors (1).

20211110261 is an equidigital number, since it uses as much as digits as its factorization.

20211110261 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 48, while the sum is 17.

Adding to 20211110261 its reverse (16201111202), we get a palindrome (36412221463).

The spelling of 20211110261 in words is "twenty billion, two hundred eleven million, one hundred ten thousand, two hundred sixty-one".