1981324800 has 1080 divisors, whose sum is σ = 9211738536. Its totient is φ = 418037760.

The previous prime is 1981324759. The next prime is 1981324817. The reversal of 1981324800 is 84231891.

It is a tau number, because it is divible by the number of its divisors (1080).

It is a super-3 number, since 3×1981324800³ (a number of 29 digits) contains 333 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 107 ways as a sum of consecutive naturals, for example, 152409594 + ... + 152409606.

Almost surely, 2^1981324800 is an apocalyptic number.

1981324800 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 1981324800, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (4605869268).

1981324800 is an abundant number, since it is smaller than the sum of its proper divisors (7230413736).

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

1981324800 is an equidigital number, since it uses as much as digits as its factorization.

1981324800 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 70 (or 30 counting only the distinct ones).

The product of its (nonzero) digits is 13824, while the sum is 36.

The square root of 1981324800 is about 44512.0747662923. The cubic root of 1981324800 is about 1255.9872339703.

The spelling of 1981324800 in words is "one billion, nine hundred eighty-one million, three hundred twenty-four thousand, eight hundred".