1999002078 has 96 divisors (see below), whose sum is σ = 4662927360. Its totient is φ = 641170080.

The previous prime is 1999002067. The next prime is 1999002079. The reversal of 1999002078 is 8702009991.

It is a hoax number, since the sum of its digits (45) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1999002079) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 4173043 + ... + 4173521.

It is an arithmetic number, because the mean of its divisors is an integer number (48572160).

Almost surely, 2^1999002078 is an apocalyptic number.

1999002078 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 1999002078, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2331463680).

1999002078 is an abundant number, since it is smaller than the sum of its proper divisors (2663925282).

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

1999002078 is a wasteful number, since it uses less digits than its factorization.

1999002078 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 804 (or 792 counting only the distinct ones).

The product of its (nonzero) digits is 81648, while the sum is 45.

The square root of 1999002078 is about 44710.2010507669. The cubic root of 1999002078 is about 1259.7114645437.

The spelling of 1999002078 in words is "one billion, nine hundred ninety-nine million, two thousand, seventy-eight".