1938071891808 has 288 divisors, whose sum is σ = 6263017225920. Its totient is φ = 563991183360.

The previous prime is 1938071891797. The next prime is 1938071891809. The reversal of 1938071891808 is 8081981708391.

1938071891808 is a `hidden beast` number, since 1 + 9 + 380 + 71 + 8 + 9 + 180 + 8 = 666.

It is a tau number, because it is divible by the number of its divisors (288).

It is a super-2 number, since 2×1938071891808² (a number of 25 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1938071891809) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 7537528 + ... + 7790408.

It is an arithmetic number, because the mean of its divisors is an integer number (21746587590).

Almost surely, 2^{1938071891808} is an apocalyptic number.

1938071891808 is a gapful number since it is divisible by the number (18) 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 1938071891808, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3131508612960).

1938071891808 is an abundant number, since it is smaller than the sum of its proper divisors (4324945334112).

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

1938071891808 is a wasteful number, since it uses less digits than its factorization.

1938071891808 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 253022 (or 253011 counting only the distinct ones).

The product of its (nonzero) digits is 6967296, while the sum is 63.

The spelling of 1938071891808 in words is "one trillion, nine hundred thirty-eight billion, seventy-one million, eight hundred ninety-one thousand, eight hundred eight".