1999323648 has 400 divisors, whose sum is σ = 6987302784. Its totient is φ = 557383680.

The previous prime is 1999323637. The next prime is 1999323649. The reversal of 1999323648 is 8463239991.

1999323648 is a `hidden beast` number, since 199 + 93 + 2 + 364 + 8 = 666.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a nude number because it is divisible by every one of its digits.

It is a junction number, because it is equal to n+sod(n) for n = 1999323594 and 1999323603.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1999323649) by changing a digit.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 20611536 + ... + 20611632.

Almost surely, 2^1999323648 is an apocalyptic number.

1999323648 is a gapful number since it is divisible by the number (18) 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 1999323648, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3493651392).

1999323648 is an abundant number, since it is smaller than the sum of its proper divisors (4987979136).

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

1999323648 is an frugal number, since it uses more digits than its factorization.

1999323648 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 205 (or 180 counting only the distinct ones).

The product of its digits is 2519424, while the sum is 54.

The square root of 1999323648 is about 44713.7970653354. The cubic root of 1999323648 is about 1259.7790088617.

The spelling of 1999323648 in words is "one billion, nine hundred ninety-nine million, three hundred twenty-three thousand, six hundred forty-eight".