1971881537040 has 640 divisors, whose sum is σ = 7247536128000. Its totient is φ = 491979847680.

The previous prime is 1971881536997. The next prime is 1971881537051. The reversal of 1971881537040 is 407351881791.

1971881537040 is a `hidden beast` number, since 1 + 97 + 18 + 8 + 1 + 537 + 0 + 4 + 0 = 666.

It is a super-2 number, since 2×1971881537040² (a number of 25 digits) contains 22 as substring.

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

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 261207186 + ... + 261214734.

It is an arithmetic number, because the mean of its divisors is an integer number (11324275200).

Almost surely, 2^{1971881537040} is an apocalyptic number.

1971881537040 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 1971881537040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3623768064000).

1971881537040 is an abundant number, since it is smaller than the sum of its proper divisors (5275654590960).

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

1971881537040 is a wasteful number, since it uses less digits than its factorization.

1971881537040 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7732 (or 7720 counting only the distinct ones).

The product of its (nonzero) digits is 1693440, while the sum is 54.

The spelling of 1971881537040 in words is "one trillion, nine hundred seventy-one billion, eight hundred eighty-one million, five hundred thirty-seven thousand, forty".