1990857000 has 512 divisors, whose sum is σ = 7353815040. Its totient is φ = 443520000.

The previous prime is 1990856971. The next prime is 1990857013. The reversal of 1990857000 is 7580991.

It is a happy number.

It is a self number, because there is not a number n which added to its sum of digits gives 1990857000.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 32636970 + ... + 32637030.

It is an arithmetic number, because the mean of its divisors is an integer number (14362920).

Almost surely, 2^1990857000 is an apocalyptic number.

1990857000 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 1990857000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3676907520).

1990857000 is an abundant number, since it is smaller than the sum of its proper divisors (5362958040).

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

1990857000 is a wasteful number, since it uses less digits than its factorization.

1990857000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 162 (or 148 counting only the distinct ones).

The product of its (nonzero) digits is 22680, while the sum is 39.

The square root of 1990857000 is about 44619.0206078081. The cubic root of 1990857000 is about 1257.9982071263.

The spelling of 1990857000 in words is "one billion, nine hundred ninety million, eight hundred fifty-seven thousand".