1211388749 has 2 divisors, whose sum is σ = 1211388750. Its totient is φ = 1211388748.

The previous prime is 1211388727. The next prime is 1211388751. The reversal of 1211388749 is 9478831121.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1108224100 + 103164649 = 33290^2 + 10157^2 .

It is an emirp because it is prime and its reverse (9478831121) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1211388749 - 2²⁸ = 942953293 is a prime.

It is a super-3 number, since 3×1211388749³ (a number of 28 digits) contains 333 as substring.

Together with 1211388751, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1211381749) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 605694374 + 605694375.

It is an arithmetic number, because the mean of its divisors is an integer number (605694375).

Almost surely, 2^1211388749 is an apocalyptic number.

It is an amenable number.

1211388749 is a deficient number, since it is larger than the sum of its proper divisors (1).

1211388749 is an equidigital number, since it uses as much as digits as its factorization.

1211388749 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 96768, while the sum is 44.

The square root of 1211388749 is about 34805.0104008029. The cubic root of 1211388749 is about 1066.0097541896.

The spelling of 1211388749 in words is "one billion, two hundred eleven million, three hundred eighty-eight thousand, seven hundred forty-nine".