27781668 has 36 divisors (see below), whose sum is σ = 70394688. Its totient is φ = 9238320.

The previous prime is 27781651. The next prime is 27781697. The reversal of 27781668 is 86618772.

It is a tau number, because it is divible by the number of its divisors (36).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 22105 + ... + 23327.

It is an arithmetic number, because the mean of its divisors is an integer number (1955408).

Almost surely, 2^27781668 is an apocalyptic number.

It is an amenable number.

27781668 is an abundant number, since it is smaller than the sum of its proper divisors (42613020).

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

27781668 is a wasteful number, since it uses less digits than its factorization.

27781668 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1864 (or 1859 counting only the distinct ones).

The product of its digits is 225792, while the sum is 45.

The square root of 27781668 is about 5270.8318129115. The cubic root of 27781668 is about 302.8675694846.

The spelling of 27781668 in words is "twenty-seven million, seven hundred eighty-one thousand, six hundred sixty-eight".