1899990000 has 400 divisors, whose sum is σ = 7065738240. Its totient is φ = 488160000.

The previous prime is 1899989999. The next prime is 1899990007. The reversal of 1899990000 is 999981.

It is a tau number, because it is divible by the number of its divisors (400).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1899990007) by changing a digit.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 8369887 + ... + 8370113.

Almost surely, 2^1899990000 is an apocalyptic number.

1899990000 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 1899990000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3532869120).

1899990000 is an abundant number, since it is smaller than the sum of its proper divisors (5165748240).

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

1899990000 is a wasteful number, since it uses less digits than its factorization.

1899990000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 295 (or 268 counting only the distinct ones).

The product of its (nonzero) digits is 52488, while the sum is 45.

The square root of 1899990000 is about 43588.8747273889. The cubic root of 1899990000 is about 1238.5601567100.

The spelling of 1899990000 in words is "one billion, eight hundred ninety-nine million, nine hundred ninety thousand".