1999428864 has 72 divisors (see below), whose sum is σ = 5331406080. Its totient is φ = 665223168.

The previous prime is 1999428853. The next prime is 1999428889. The reversal of 1999428864 is 4688249991.

It is a junction number, because it is equal to n+sod(n) for n = 1999428798 and 1999428807.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 464032 + ... + 468320.

Almost surely, 2^1999428864 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1999428864, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2665703040).

1999428864 is an abundant number, since it is smaller than the sum of its proper divisors (3331977216).

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

1999428864 is an equidigital number, since it uses as much as digits as its factorization.

1999428864 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4915 (or 4901 counting only the distinct ones).

The product of its digits is 8957952, while the sum is 60.

The square root of 1999428864 is about 44714.9735994555. The cubic root of 1999428864 is about 1259.8011074321.

The spelling of 1999428864 in words is "one billion, nine hundred ninety-nine million, four hundred twenty-eight thousand, eight hundred sixty-four".