1211111201 has 2 divisors, whose sum is σ = 1211111202. Its totient is φ = 1211111200.

The previous prime is 1211111189. The next prime is 1211111249. The reversal of 1211111201 is 1021111121.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1211109601 + 1600 = 34801^2 + 40^2 .

It is an emirp because it is prime and its reverse (1021111121) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1211111201 - 2¹⁴ = 1211094817 is a prime.

It is not a weakly prime, because it can be changed into another prime (1211111101) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 605555600 + 605555601.

It is an arithmetic number, because the mean of its divisors is an integer number (605555601).

Almost surely, 2^1211111201 is an apocalyptic number.

It is an amenable number.

1211111201 is a deficient number, since it is larger than the sum of its proper divisors (1).

1211111201 is an equidigital number, since it uses as much as digits as its factorization.

1211111201 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4, while the sum is 11.

The square root of 1211111201 is about 34801.0229878376. The cubic root of 1211111201 is about 1065.9283348340.

Adding to 1211111201 its reverse (1021111121), we get a palindrome (2232222322).

It can be divided in two parts, 121111120 and 1, that added together give a palindrome (121111121).

The spelling of 1211111201 in words is "one billion, two hundred eleven million, one hundred eleven thousand, two hundred one".