1999901768 has 36 divisors (see below), whose sum is σ = 3812259465. Its totient is φ = 983570688.

The previous prime is 1999901767. The next prime is 1999901779. The reversal of 1999901768 is 8671099991.

It is a powerful number, because all its prime factors have an exponent greater than 1 and also an Achilles number because it is not a perfect power.

It can be written as a sum of positive squares in 2 ways, for example, as 1994694244 + 5207524 = 44662^2 + 2282^2 .

It is an ABA number since it can be written as A⋅B^A, here for A=2, B=31622.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1999901767) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 12269255 + ... + 12269417.

Almost surely, 2^1999901768 is an apocalyptic number.

It is an amenable number.

1999901768 is a deficient number, since it is larger than the sum of its proper divisors (1812357697).

1999901768 is an frugal number, since it uses more digits than its factorization.

1999901768 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 526 (or 262 counting only the distinct ones).

The product of its (nonzero) digits is 2204496, while the sum is 59.

The square root of 1999901768 is about 44720.2612693620. The cubic root of 1999901768 is about 1259.9004221297.

The spelling of 1999901768 in words is "one billion, nine hundred ninety-nine million, nine hundred one thousand, seven hundred sixty-eight".