2111220101261 has 2 divisors, whose sum is σ = 2111220101262. Its totient is φ = 2111220101260.

The previous prime is 2111220101197. The next prime is 2111220101267. The reversal of 2111220101261 is 1621010221112.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1081007281225 + 1030212820036 = 1039715^2 + 1014994^2 .

It is a cyclic number.

It is not a de Polignac number, because 2111220101261 - 2⁶ = 2111220101197 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2111220101267) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1055610050630 + 1055610050631.

It is an arithmetic number, because the mean of its divisors is an integer number (1055610050631).

Almost surely, 2^{2111220101261} is an apocalyptic number.

It is an amenable number.

2111220101261 is a deficient number, since it is larger than the sum of its proper divisors (1).

2111220101261 is an equidigital number, since it uses as much as digits as its factorization.

2111220101261 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 2111220101261 its reverse (1621010221112), we get a palindrome (3732230322373).

The spelling of 2111220101261 in words is "two trillion, one hundred eleven billion, two hundred twenty million, one hundred one thousand, two hundred sixty-one".