1298680309 has 4 divisors (see below), whose sum is σ = 1299005100. Its totient is φ = 1298355520.

The previous prime is 1298680307. The next prime is 1298680319. The reversal of 1298680309 is 9030868921.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 627352209 + 671328100 = 25047^2 + 25910^2 .

It is a cyclic number.

It is not a de Polignac number, because 1298680309 - 2¹ = 1298680307 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1298680307) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 156322 + ... + 164419.

It is an arithmetic number, because the mean of its divisors is an integer number (324751275).

Almost surely, 2^1298680309 is an apocalyptic number.

It is an amenable number.

1298680309 is a deficient number, since it is larger than the sum of its proper divisors (324791).

1298680309 is an equidigital number, since it uses as much as digits as its factorization.

1298680309 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 324790.

The product of its (nonzero) digits is 186624, while the sum is 46.

The square root of 1298680309 is about 36037.2072863589. The cubic root of 1298680309 is about 1091.0234499809.

The spelling of 1298680309 in words is "one billion, two hundred ninety-eight million, six hundred eighty thousand, three hundred nine".