1209681139 has 2 divisors, whose sum is σ = 1209681140. Its totient is φ = 1209681138.

The previous prime is 1209681133. The next prime is 1209681199. The reversal of 1209681139 is 9311869021.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1209681139 - 2²¹ = 1207583987 is a prime.

It is not a weakly prime, because it can be changed into another prime (1209681133) 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, 604840569 + 604840570.

It is an arithmetic number, because the mean of its divisors is an integer number (604840570).

Almost surely, 2^1209681139 is an apocalyptic number.

1209681139 is a deficient number, since it is larger than the sum of its proper divisors (1).

1209681139 is an equidigital number, since it uses as much as digits as its factorization.

1209681139 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 23328, while the sum is 40.

The square root of 1209681139 is about 34780.4706552398. The cubic root of 1209681139 is about 1065.5086255144.

The spelling of 1209681139 in words is "one billion, two hundred nine million, six hundred eighty-one thousand, one hundred thirty-nine".