1998944653 has 2 divisors, whose sum is σ = 1998944654. Its totient is φ = 1998944652.

The previous prime is 1998944621. The next prime is 1998944671. The reversal of 1998944653 is 3564498991.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1624251204 + 374693449 = 40302^2 + 19357^2 .

It is a cyclic number.

It is not a de Polignac number, because 1998944653 - 2⁵ = 1998944621 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1998344653) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 999472326 + 999472327.

It is an arithmetic number, because the mean of its divisors is an integer number (999472327).

Almost surely, 2^1998944653 is an apocalyptic number.

It is an amenable number.

1998944653 is a deficient number, since it is larger than the sum of its proper divisors (1).

1998944653 is an equidigital number, since it uses as much as digits as its factorization.

1998944653 is an evil number, because the sum of its binary digits is even.

The product of its digits is 8398080, while the sum is 58.

The square root of 1998944653 is about 44709.5588549026. The cubic root of 1998944653 is about 1259.6994019210.

The spelling of 1998944653 in words is "one billion, nine hundred ninety-eight million, nine hundred forty-four thousand, six hundred fifty-three".