1999799890 has 32 divisors (see below), whose sum is σ = 3929420160. Its totient is φ = 726729600.

The previous prime is 1999799843. The next prime is 1999799909. The reversal of 1999799890 is 989979991.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 196446 + ... + 206374.

It is an arithmetic number, because the mean of its divisors is an integer number (122794380).

Almost surely, 2^1999799890 is an apocalyptic number.

1999799890 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

1999799890 is a deficient number, since it is larger than the sum of its proper divisors (1929620270).

1999799890 is a wasteful number, since it uses less digits than its factorization.

1999799890 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11778.

The product of its (nonzero) digits is 29760696, while the sum is 70.

The square root of 1999799890 is about 44719.1221962149. The cubic root of 1999799890 is about 1259.8790280265.

It can be divided in two parts, 199 and 9799890, that added together give a palindrome (9800089).

The spelling of 1999799890 in words is "one billion, nine hundred ninety-nine million, seven hundred ninety-nine thousand, eight hundred ninety".