1999680 has 56 divisors (see below), whose sum is σ = 6352032. Its totient is φ = 532992.

The previous prime is 1999667. The next prime is 1999681. The reversal of 1999680 is 869991.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1999681) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 82 + ... + 2001.

2^1999680 is an apocalyptic number.

1999680 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 1999680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3176016).

1999680 is an abundant number, since it is smaller than the sum of its proper divisors (4352352).

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

1999680 is a wasteful number, since it uses less digits than its factorization.

1999680 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2103 (or 2093 counting only the distinct ones).

The product of its (nonzero) digits is 34992, while the sum is 42.

The square root of 1999680 is about 1414.1004207623. The cubic root of 1999680 is about 125.9853850521.

It can be divided in two parts, 19 and 99680, that added together give a palindrome (99699).

The spelling of 1999680 in words is "one million, nine hundred ninety-nine thousand, six hundred eighty".