27981663840 has 1152 divisors, whose sum is σ = 116501898240. Its totient is φ = 6284500992.

The previous prime is 27981663833. The next prime is 27981663901. The reversal of 27981663840 is 4836618972.

It is a super-3 number, since 3×27981663840³ (a number of 32 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 337128439 + ... + 337128521.

It is an arithmetic number, because the mean of its divisors is an integer number (101130120).

Almost surely, 2^27981663840 is an apocalyptic number.

27981663840 is a gapful number since it is divisible by the number (20) 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 27981663840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (58250949120).

27981663840 is an abundant number, since it is smaller than the sum of its proper divisors (88520234400).

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

27981663840 is a wasteful number, since it uses less digits than its factorization.

27981663840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 178 (or 158 counting only the distinct ones).

The product of its (nonzero) digits is 3483648, while the sum is 54.

The spelling of 27981663840 in words is "twenty-seven billion, nine hundred eighty-one million, six hundred sixty-three thousand, eight hundred forty".