1971385827840 has 2240 divisors, whose sum is σ = 8520755886720. Its totient is φ = 430937210880.

The previous prime is 1971385827811. The next prime is 1971385827883. The reversal of 1971385827840 is 487285831791.

1971385827840 is a `hidden beast` number, since 1 + 9 + 7 + 1 + 3 + 8 + 582 + 7 + 8 + 40 = 666.

It is an unprimeable number.

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 223 ways as a sum of consecutive naturals, for example, 22150402516 + ... + 22150402604.

It is an arithmetic number, because the mean of its divisors is an integer number (3803908878).

Almost surely, 2^{1971385827840} is an apocalyptic number.

1971385827840 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 1971385827840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (4260377943360).

1971385827840 is an abundant number, since it is smaller than the sum of its proper divisors (6549370058880).

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

1971385827840 is an equidigital number, since it uses as much as digits as its factorization.

1971385827840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 237 (or 206 counting only the distinct ones).

The product of its (nonzero) digits is 27095040, while the sum is 63.

The spelling of 1971385827840 in words is "one trillion, nine hundred seventy-one billion, three hundred eighty-five million, eight hundred twenty-seven thousand, eight hundred forty".