1999101720 has 512 divisors, whose sum is σ = 8045568000. Its totient is φ = 384860160.

The previous prime is 1999101707. The next prime is 1999101733. The reversal of 1999101720 is 271019991.

It is an interprime number because it is at equal distance from previous prime (1999101707) and next prime (1999101733).

It is a congruent number.

It is an unprimeable number.

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 127 ways as a sum of consecutive naturals, for example, 10357944 + ... + 10358136.

It is an arithmetic number, because the mean of its divisors is an integer number (15714000).

Almost surely, 2^1999101720 is an apocalyptic number.

1999101720 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 1999101720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (4022784000).

1999101720 is an abundant number, since it is smaller than the sum of its proper divisors (6046466280).

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

1999101720 is a wasteful number, since it uses less digits than its factorization.

1999101720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 303 (or 299 counting only the distinct ones).

The product of its (nonzero) digits is 10206, while the sum is 39.

The square root of 1999101720 is about 44711.3153463416. The cubic root of 1999101720 is about 1259.7323946677.

The spelling of 1999101720 in words is "one billion, nine hundred ninety-nine million, one hundred one thousand, seven hundred twenty".