1211115641 has 2 divisors, whose sum is σ = 1211115642. Its totient is φ = 1211115640.

The previous prime is 1211115637. The next prime is 1211115673. The reversal of 1211115641 is 1465111121.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1210761616 + 354025 = 34796^2 + 595^2 .

It is an emirp because it is prime and its reverse (1465111121) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1211115641 - 2² = 1211115637 is a prime.

It is not a weakly prime, because it can be changed into another prime (1211115691) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 605557820 + 605557821.

It is an arithmetic number, because the mean of its divisors is an integer number (605557821).

Almost surely, 2^1211115641 is an apocalyptic number.

It is an amenable number.

1211115641 is a deficient number, since it is larger than the sum of its proper divisors (1).

1211115641 is an equidigital number, since it uses as much as digits as its factorization.

1211115641 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 240, while the sum is 23.

The square root of 1211115641 is about 34801.0867790073. The cubic root of 1211115641 is about 1065.9296374163.

Adding to 1211115641 its reverse (1465111121), we get a palindrome (2676226762).

The spelling of 1211115641 in words is "one billion, two hundred eleven million, one hundred fifteen thousand, six hundred forty-one".