27990666 has 48 divisors (see below), whose sum is σ = 66512160. Its totient is φ = 8436960.

The previous prime is 27990661. The next prime is 27990679. The reversal of 27990666 is 66609972.

It is not an unprimeable number, because it can be changed into a prime (27990661) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 73665 + ... + 74043.

It is an arithmetic number, because the mean of its divisors is an integer number (1385670).

Almost surely, 2^27990666 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 27990666, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33256080).

27990666 is an abundant number, since it is smaller than the sum of its proper divisors (38521494).

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

27990666 is a wasteful number, since it uses less digits than its factorization.

27990666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 771 (or 768 counting only the distinct ones).

The product of its (nonzero) digits is 244944, while the sum is 45.

The square root of 27990666 is about 5290.6205685156. The cubic root of 27990666 is about 303.6251511500.

It can be divided in two parts, 279906 and 66, that added together give a palindrome (279972).

The spelling of 27990666 in words is "twenty-seven million, nine hundred ninety thousand, six hundred sixty-six".