1981259280 has 480 divisors, whose sum is σ = 8936928000. Its totient is φ = 379883520.

The previous prime is 1981259279. The next prime is 1981259299. The reversal of 1981259280 is 829521891.

It is a super-3 number, since 3×1981259280³ (a number of 29 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a hoax number, since the sum of its digits (45) coincides with the sum of the digits of its distinct prime factors.

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 95 ways as a sum of consecutive naturals, for example, 719346 + ... + 722094.

It is an arithmetic number, because the mean of its divisors is an integer number (18618600).

Almost surely, 2^1981259280 is an apocalyptic number.

1981259280 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 1981259280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (4468464000).

1981259280 is an abundant number, since it is smaller than the sum of its proper divisors (6955668720).

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

1981259280 is a wasteful number, since it uses less digits than its factorization.

1981259280 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2799 (or 2790 counting only the distinct ones).

The product of its (nonzero) digits is 103680, while the sum is 45.

The square root of 1981259280 is about 44511.3387801356. The cubic root of 1981259280 is about 1255.9733891613.

The spelling of 1981259280 in words is "one billion, nine hundred eighty-one million, two hundred fifty-nine thousand, two hundred eighty".