1998454309 has 2 divisors, whose sum is σ = 1998454310. Its totient is φ = 1998454308.

The previous prime is 1998454303. The next prime is 1998454321. The reversal of 1998454309 is 9034548991.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1998358209 + 96100 = 44703^2 + 310^2 .

It is a cyclic number.

It is not a de Polignac number, because 1998454309 - 2⁹ = 1998453797 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1998454303) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 999227154 + 999227155.

It is an arithmetic number, because the mean of its divisors is an integer number (999227155).

Almost surely, 2^1998454309 is an apocalyptic number.

It is an amenable number.

1998454309 is a deficient number, since it is larger than the sum of its proper divisors (1).

1998454309 is an equidigital number, since it uses as much as digits as its factorization.

1998454309 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1399680, while the sum is 52.

The square root of 1998454309 is about 44704.0748590103. The cubic root of 1998454309 is about 1259.5963914723.

The spelling of 1998454309 in words is "one billion, nine hundred ninety-eight million, four hundred fifty-four thousand, three hundred nine".