27728746638 has 16 divisors (see below), whose sum is σ = 57246445056. Its totient is φ = 8944756920.

The previous prime is 27728746589. The next prime is 27728746657. The reversal of 27728746638 is 83664782772.

It is a super-2 number, since 2×27728746638² (a number of 22 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 74539456 + ... + 74539827.

It is an arithmetic number, because the mean of its divisors is an integer number (3577902816).

Almost surely, 2^27728746638 is an apocalyptic number.

27728746638 is an abundant number, since it is smaller than the sum of its proper divisors (29517698418).

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

27728746638 is a wasteful number, since it uses less digits than its factorization.

27728746638 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 149079319.

The product of its digits is 37933056, while the sum is 60.

The spelling of 27728746638 in words is "twenty-seven billion, seven hundred twenty-eight million, seven hundred forty-six thousand, six hundred thirty-eight".