1298121309 has 24 divisors (see below), whose sum is σ = 2058900480. Its totient is φ = 814504896.

The previous prime is 1298121277. The next prime is 1298121323. The reversal of 1298121309 is 9031218921.

It is not a de Polignac number, because 1298121309 - 2⁵ = 1298121277 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1298121379) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 152989 + ... + 161250.

It is an arithmetic number, because the mean of its divisors is an integer number (85787520).

Almost surely, 2^1298121309 is an apocalyptic number.

It is an amenable number.

1298121309 is a deficient number, since it is larger than the sum of its proper divisors (760779171).

1298121309 is an equidigital number, since it uses as much as digits as its factorization.

1298121309 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 314271 (or 314259 counting only the distinct ones).

The product of its (nonzero) digits is 7776, while the sum is 36.

The square root of 1298121309 is about 36029.4505786586. The cubic root of 1298121309 is about 1090.8668885776.

The spelling of 1298121309 in words is "one billion, two hundred ninety-eight million, one hundred twenty-one thousand, three hundred nine".