1999880 has 48 divisors (see below), whose sum is σ = 4807620. Its totient is φ = 748544.

The previous prime is 1999871. The next prime is 1999889. The reversal of 1999880 is 889991.

It is an interprime number because it is at equal distance from previous prime (1999871) and next prime (1999889).

It can be written as a sum of positive squares in 6 ways, for example, as 1800964 + 198916 = 1342^2 + 446^2 .

It is not an unprimeable number, because it can be changed into a prime (1999889) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 11474 + ... + 11646.

2^1999880 is an apocalyptic number.

1999880 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1999880, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2403810).

1999880 is an abundant number, since it is smaller than the sum of its proper divisors (2807740).

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

1999880 is a wasteful number, since it uses less digits than its factorization.

1999880 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 218 (or 197 counting only the distinct ones).

The product of its (nonzero) digits is 46656, while the sum is 44.

The square root of 1999880 is about 1414.1711353298. The cubic root of 1999880 is about 125.9895850970.

It can be divided in two parts, 19 and 99880, that added together give a palindrome (99899).

The spelling of 1999880 in words is "one million, nine hundred ninety-nine thousand, eight hundred eighty".