1990868544 has 280 divisors, whose sum is σ = 6836225088. Its totient is φ = 561116160.

The previous prime is 1990868543. The next prime is 1990868549. The reversal of 1990868544 is 4458680991.

1990868544 is a `hidden beast` number, since 1 + 9 + 90 + 8 + 6 + 8 + 544 = 666.

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

It is not an unprimeable number, because it can be changed into a prime (1990868543) 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, 3011574 + ... + 3012234.

Almost surely, 2^1990868544 is an apocalyptic number.

1990868544 is a gapful number since it is divisible by the number (14) 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 1990868544, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3418112544).

1990868544 is an abundant number, since it is smaller than the sum of its proper divisors (4845356544).

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

1990868544 is an equidigital number, since it uses as much as digits as its factorization.

1990868544 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 775 (or 756 counting only the distinct ones).

The product of its (nonzero) digits is 2488320, while the sum is 54.

The square root of 1990868544 is about 44619.1499694918. The cubic root of 1990868544 is about 1258.0006386258. Note that the first 3 decimals are identical.

The spelling of 1990868544 in words is "one billion, nine hundred ninety million, eight hundred sixty-eight thousand, five hundred forty-four".