1211218849 has 2 divisors, whose sum is σ = 1211218850. Its totient is φ = 1211218848.

The previous prime is 1211218829. The next prime is 1211218871. The reversal of 1211218849 is 9488121121.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 614296225 + 596922624 = 24785^2 + 24432^2 .

It is a cyclic number.

It is not a de Polignac number, because 1211218849 - 2⁵ = 1211218817 is a prime.

It is a super-2 number, since 2×1211218849² = 2934102200345769602, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (1211218819) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 605609424 + 605609425.

It is an arithmetic number, because the mean of its divisors is an integer number (605609425).

Almost surely, 2^1211218849 is an apocalyptic number.

It is an amenable number.

1211218849 is a deficient number, since it is larger than the sum of its proper divisors (1).

1211218849 is an equidigital number, since it uses as much as digits as its factorization.

1211218849 is an evil number, because the sum of its binary digits is even.

The product of its digits is 9216, while the sum is 37.

The square root of 1211218849 is about 34802.5695746736. The cubic root of 1211218849 is about 1065.9599151033.

The spelling of 1211218849 in words is "one billion, two hundred eleven million, two hundred eighteen thousand, eight hundred forty-nine".