1990209000 has 128 divisors (see below), whose sum is σ = 6687233280. Its totient is φ = 489888000.

The previous prime is 1990208981. The next prime is 1990209007. The reversal of 1990209000 is 9020991.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is not an unprimeable number, because it can be changed into a prime (1990209007) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 13485 + ... + 64515.

It is an arithmetic number, because the mean of its divisors is an integer number (52244010).

Almost surely, 2^1990209000 is an apocalyptic number.

1990209000 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 1990209000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3343616640).

1990209000 is an abundant number, since it is smaller than the sum of its proper divisors (4697024280).

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

1990209000 is a wasteful number, since it uses less digits than its factorization.

1990209000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 51068 (or 51054 counting only the distinct ones).

The product of its (nonzero) digits is 1458, while the sum is 30.

The square root of 1990209000 is about 44611.7585396496. The cubic root of 1990209000 is about 1257.8617045551.

Adding to 1990209000 its reverse (9020991), we get a palindrome (1999229991).

The spelling of 1990209000 in words is "one billion, nine hundred ninety million, two hundred nine thousand".