1229109781 has 2 divisors, whose sum is σ = 1229109782. Its totient is φ = 1229109780.

The previous prime is 1229109757. The next prime is 1229109787. The reversal of 1229109781 is 1879019221.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1128288100 + 100821681 = 33590^2 + 10041^2 .

It is a cyclic number.

It is not a de Polignac number, because 1229109781 - 2²¹ = 1227012629 is a prime.

It is a super-2 number, since 2×1229109781² = 3021421707499735922, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1229109787) 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, 614554890 + 614554891.

It is an arithmetic number, because the mean of its divisors is an integer number (614554891).

Almost surely, 2^1229109781 is an apocalyptic number.

It is an amenable number.

1229109781 is a deficient number, since it is larger than the sum of its proper divisors (1).

1229109781 is an equidigital number, since it uses as much as digits as its factorization.

1229109781 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 18144, while the sum is 40.

The square root of 1229109781 is about 35058.6619967163. The cubic root of 1229109781 is about 1071.1827202115.

The spelling of 1229109781 in words is "one billion, two hundred twenty-nine million, one hundred nine thousand, seven hundred eighty-one".