191220110101 has 2 divisors, whose sum is σ = 191220110102. Its totient is φ = 191220110100.

The previous prime is 191220110093. The next prime is 191220110143. The reversal of 191220110101 is 101011022191.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 147666507076 + 43553603025 = 384274^2 + 208695^2 .

It is a cyclic number.

It is not a de Polignac number, because 191220110101 - 2³ = 191220110093 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (191220110161) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 95610055050 + 95610055051.

It is an arithmetic number, because the mean of its divisors is an integer number (95610055051).

Almost surely, 2^191220110101 is an apocalyptic number.

It is an amenable number.

191220110101 is a deficient number, since it is larger than the sum of its proper divisors (1).

191220110101 is an equidigital number, since it uses as much as digits as its factorization.

191220110101 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 36, while the sum is 19.

Adding to 191220110101 its reverse (101011022191), we get a palindrome (292231132292).

The spelling of 191220110101 in words is "one hundred ninety-one billion, two hundred twenty million, one hundred ten thousand, one hundred one".