1981594000 has 40 divisors (see below), whose sum is σ = 4791499128. Its totient is φ = 792636800.

The previous prime is 1981593959. The next prime is 1981594007. The reversal of 1981594000 is 4951891.

It can be written as a sum of positive squares in 4 ways, for example, as 530288784 + 1451305216 = 23028^2 + 38096^2 .

It is a tau number, because it is divible by the number of its divisors (40).

It is not an unprimeable number, because it can be changed into a prime (1981594007) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 493399 + ... + 497398.

Almost surely, 2^1981594000 is an apocalyptic number.

1981594000 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1981594000 is an abundant number, since it is smaller than the sum of its proper divisors (2809905128).

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

1981594000 is an equidigital number, since it uses as much as digits as its factorization.

1981594000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 990820 (or 990804 counting only the distinct ones).

The product of its (nonzero) digits is 12960, while the sum is 37.

The square root of 1981594000 is about 44515.0985621733. The cubic root of 1981594000 is about 1256.0441145066.

The spelling of 1981594000 in words is "one billion, nine hundred eighty-one million, five hundred ninety-four thousand".