1999633720 has 128 divisors (see below), whose sum is σ = 5431680000. Its totient is φ = 647212032.

The previous prime is 1999633709. The next prime is 1999633729. The reversal of 1999633720 is 273369991.

It is a super-2 number, since 2×1999633720² = 7997070028322076800, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1999633729) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 2175421 + ... + 2176339.

It is an arithmetic number, because the mean of its divisors is an integer number (42435000).

Almost surely, 2^1999633720 is an apocalyptic number.

1999633720 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 1999633720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2715840000).

1999633720 is an abundant number, since it is smaller than the sum of its proper divisors (3432046280).

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

1999633720 is a wasteful number, since it uses less digits than its factorization.

1999633720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1365 (or 1361 counting only the distinct ones).

The product of its (nonzero) digits is 551124, while the sum is 49.

The square root of 1999633720 is about 44717.2642275889. The cubic root of 1999633720 is about 1259.8441312187.

The spelling of 1999633720 in words is "one billion, nine hundred ninety-nine million, six hundred thirty-three thousand, seven hundred twenty".