1989411840 has 616 divisors, whose sum is σ = 7893444888. Its totient is φ = 477757440.

The previous prime is 1989411839. The next prime is 1989411871. The reversal of 1989411840 is 481149891.

1989411840 is a `hidden beast` number, since 198 + 9 + 411 + 8 + 40 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 47775744 + 1941636096 = 6912^2 + 44064^2 .

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

It is an unprimeable number.

It is a polite number, since it can be written in 55 ways as a sum of consecutive naturals, for example, 48522220 + ... + 48522260.

Almost surely, 2^1989411840 is an apocalyptic number.

1989411840 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 1989411840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3946722444).

1989411840 is an abundant number, since it is smaller than the sum of its proper divisors (5904033048).

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

1989411840 is an equidigital number, since it uses as much as digits as its factorization.

1989411840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 97 (or 64 counting only the distinct ones).

The product of its (nonzero) digits is 82944, while the sum is 45.

The square root of 1989411840 is about 44602.8232290289. The cubic root of 1989411840 is about 1257.6937404631.

The spelling of 1989411840 in words is "one billion, nine hundred eighty-nine million, four hundred eleven thousand, eight hundred forty".