27771641688 has 128 divisors (see below), whose sum is σ = 84182630400. Its totient is φ = 7457837184.

The previous prime is 27771641687. The next prime is 27771641699. The reversal of 27771641688 is 88614617772.

It is a Harshad number since it is a multiple of its sum of digits (57).

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (27771641687) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 371131 + ... + 439637.

It is an arithmetic number, because the mean of its divisors is an integer number (657676800).

Almost surely, 2^27771641688 is an apocalyptic number.

27771641688 is a gapful number since it is divisible by the number (28) 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 27771641688, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (42091315200).

27771641688 is an abundant number, since it is smaller than the sum of its proper divisors (56410988712).

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

27771641688 is a wasteful number, since it uses less digits than its factorization.

27771641688 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 68669 (or 68665 counting only the distinct ones).

The product of its digits is 6322176, while the sum is 57.

The spelling of 27771641688 in words is "twenty-seven billion, seven hundred seventy-one million, six hundred forty-one thousand, six hundred eighty-eight".