1211021117 has 2 divisors, whose sum is σ = 1211021118. Its totient is φ = 1211021116.

The previous prime is 1211021111. The next prime is 1211021143. The reversal of 1211021117 is 7111201121.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 851122276 + 359898841 = 29174^2 + 18971^2 .

It is a cyclic number.

It is not a de Polignac number, because 1211021117 - 2¹² = 1211017021 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1211021095 and 1211021104.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1211021111) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 605510558 + 605510559.

It is an arithmetic number, because the mean of its divisors is an integer number (605510559).

Almost surely, 2^1211021117 is an apocalyptic number.

It is an amenable number.

1211021117 is a deficient number, since it is larger than the sum of its proper divisors (1).

1211021117 is an equidigital number, since it uses as much as digits as its factorization.

1211021117 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 28, while the sum is 17.

The square root of 1211021117 is about 34799.7286914711. The cubic root of 1211021117 is about 1065.9019058078.

Adding to 1211021117 its reverse (7111201121), we get a palindrome (8322222238).

The spelling of 1211021117 in words is "one billion, two hundred eleven million, twenty-one thousand, one hundred seventeen".