1299979309 has 2 divisors, whose sum is σ = 1299979310. Its totient is φ = 1299979308.

The previous prime is 1299979271. The next prime is 1299979313. The reversal of 1299979309 is 9039799921.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1267146409 + 32832900 = 35597^2 + 5730^2 .

It is an emirp because it is prime and its reverse (9039799921) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1299979309 - 2¹³ = 1299971117 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1299979319) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 649989654 + 649989655.

It is an arithmetic number, because the mean of its divisors is an integer number (649989655).

Almost surely, 2^1299979309 is an apocalyptic number.

It is an amenable number.

1299979309 is a deficient number, since it is larger than the sum of its proper divisors (1).

1299979309 is an equidigital number, since it uses as much as digits as its factorization.

1299979309 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2480058, while the sum is 58.

The square root of 1299979309 is about 36055.2258209542. The cubic root of 1299979309 is about 1091.3870927714.

The spelling of 1299979309 in words is "one billion, two hundred ninety-nine million, nine hundred seventy-nine thousand, three hundred nine".