1993443990 has 16 divisors (see below), whose sum is σ = 4784265648. Its totient is φ = 531585056.

The previous prime is 1993443989. The next prime is 1993444001. The reversal of 1993443990 is 993443991.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 33224037 + ... + 33224096.

It is an arithmetic number, because the mean of its divisors is an integer number (299016603).

Almost surely, 2^1993443990 is an apocalyptic number.

1993443990 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

1993443990 is an abundant number, since it is smaller than the sum of its proper divisors (2790821658).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1993443990 is a wasteful number, since it uses less digits than its factorization.

1993443990 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 66448143.

The product of its (nonzero) digits is 944784, while the sum is 51.

The square root of 1993443990 is about 44648.0009630890. Note that the first 3 decimals coincide. The cubic root of 1993443990 is about 1258.5428670657.

Subtracting from 1993443990 its reverse (993443991), we obtain a palindrome (999999999).

The spelling of 1993443990 in words is "one billion, nine hundred ninety-three million, four hundred forty-three thousand, nine hundred ninety".