1998593405 has 16 divisors (see below), whose sum is σ = 2480813568. Its totient is φ = 1544088000.

The previous prime is 1998593393. The next prime is 1998593407. The reversal of 1998593405 is 5043958991.

It is a happy number.

It is not a de Polignac number, because 1998593405 - 2⁶ = 1998593341 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 (1998593407) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 62975 + ... + 89235.

It is an arithmetic number, because the mean of its divisors is an integer number (155050848).

Almost surely, 2^1998593405 is an apocalyptic number.

It is an amenable number.

1998593405 is a deficient number, since it is larger than the sum of its proper divisors (482220163).

1998593405 is a wasteful number, since it uses less digits than its factorization.

1998593405 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26788.

The product of its (nonzero) digits is 1749600, while the sum is 53.

The square root of 1998593405 is about 44705.6305737879. The cubic root of 1998593405 is about 1259.6256141828.

The spelling of 1998593405 in words is "one billion, nine hundred ninety-eight million, five hundred ninety-three thousand, four hundred five".