20111102210261 has 2 divisors, whose sum is σ = 20111102210262. Its totient is φ = 20111102210260.

The previous prime is 20111102210191. The next prime is 20111102210267. The reversal of 20111102210261 is 16201220111102.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19501992203236 + 609110007025 = 4416106^2 + 780455^2 .

It is a cyclic number.

It is not a de Polignac number, because 20111102210261 - 2⁴² = 15713055699157 is a prime.

It is a super-2 number, since 2×20111102210261² (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 (20111102210267) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10055551105130 + 10055551105131.

It is an arithmetic number, because the mean of its divisors is an integer number (10055551105131).

Almost surely, 2^{20111102210261} is an apocalyptic number.

It is an amenable number.

20111102210261 is a deficient number, since it is larger than the sum of its proper divisors (1).

20111102210261 is an equidigital number, since it uses as much as digits as its factorization.

20111102210261 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 96, while the sum is 20.

Adding to 20111102210261 its reverse (16201220111102), we get a palindrome (36312322321363).

The spelling of 20111102210261 in words is "twenty trillion, one hundred eleven billion, one hundred two million, two hundred ten thousand, two hundred sixty-one".