1989917280 has 576 divisors, whose sum is σ = 7890075648. Its totient is φ = 470292480.

The previous prime is 1989917221. The next prime is 1989917287. The reversal of 1989917280 is 827199891.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1989917287) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 15668577 + ... + 15668703.

It is an arithmetic number, because the mean of its divisors is an integer number (13698048).

Almost surely, 2^1989917280 is an apocalyptic number.

1989917280 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 1989917280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3945037824).

1989917280 is an abundant number, since it is smaller than the sum of its proper divisors (5900158368).

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

1989917280 is a wasteful number, since it uses less digits than its factorization.

1989917280 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 201 (or 181 counting only the distinct ones).

The product of its (nonzero) digits is 653184, while the sum is 54.

The square root of 1989917280 is about 44608.4888782393. The cubic root of 1989917280 is about 1257.8002434478.

The spelling of 1989917280 in words is "one billion, nine hundred eighty-nine million, nine hundred seventeen thousand, two hundred eighty".