1398481309 has 2 divisors, whose sum is σ = 1398481310. Its totient is φ = 1398481308.

The previous prime is 1398481241. The next prime is 1398481327. The reversal of 1398481309 is 9031848931.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1377523225 + 20958084 = 37115^2 + 4578^2 .

It is a cyclic number.

It is not a de Polignac number, because 1398481309 - 2²⁹ = 861610397 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1398481109) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 699240654 + 699240655.

It is an arithmetic number, because the mean of its divisors is an integer number (699240655).

Almost surely, 2^1398481309 is an apocalyptic number.

It is an amenable number.

1398481309 is a deficient number, since it is larger than the sum of its proper divisors (1).

1398481309 is an equidigital number, since it uses as much as digits as its factorization.

1398481309 is an evil number, because the sum of its binary digits is even.

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

The square root of 1398481309 is about 37396.2739988892. The cubic root of 1398481309 is about 1118.2842855279.

The spelling of 1398481309 in words is "one billion, three hundred ninety-eight million, four hundred eighty-one thousand, three hundred nine".