1101111221261 has 2 divisors, whose sum is σ = 1101111221262. Its totient is φ = 1101111221260.

The previous prime is 1101111221201. The next prime is 1101111221267. The reversal of 1101111221261 is 1621221111011.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 967480763236 + 133630458025 = 983606^2 + 365555^2 .

It is a cyclic number.

It is not a de Polignac number, because 1101111221261 - 2¹⁴ = 1101111204877 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1101111221267) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 550555610630 + 550555610631.

It is an arithmetic number, because the mean of its divisors is an integer number (550555610631).

Almost surely, 2^{1101111221261} is an apocalyptic number.

It is an amenable number.

1101111221261 is a deficient number, since it is larger than the sum of its proper divisors (1).

1101111221261 is an equidigital number, since it uses as much as digits as its factorization.

1101111221261 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 48, while the sum is 20.

Adding to 1101111221261 its reverse (1621221111011), we get a palindrome (2722332332272).

The spelling of 1101111221261 in words is "one trillion, one hundred one billion, one hundred eleven million, two hundred twenty-one thousand, two hundred sixty-one".