27981636672 has 56 divisors (see below), whose sum is σ = 80765184672. Its totient is φ = 8479283200.

The previous prime is 27981636653. The next prime is 27981636673. The reversal of 27981636672 is 27663618972.

It is not an unprimeable number, because it can be changed into a prime (27981636673) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6622329 + ... + 6626552.

Almost surely, 2^27981636672 is an apocalyptic number.

27981636672 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is an amenable number.

27981636672 is an abundant number, since it is smaller than the sum of its proper divisors (52783548000).

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

27981636672 is a wasteful number, since it uses less digits than its factorization.

27981636672 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13248907 (or 13248897 counting only the distinct ones).

The product of its digits is 9144576, while the sum is 57.

The spelling of 27981636672 in words is "twenty-seven billion, nine hundred eighty-one million, six hundred thirty-six thousand, six hundred seventy-two".