27638993 has 4 divisors (see below), whose sum is σ = 27706980. Its totient is φ = 27571008.

The previous prime is 27638987. The next prime is 27639013. The reversal of 27638993 is 39983672.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 19298449 + 8340544 = 4393^2 + 2888^2 .

It is a cyclic number.

It is not a de Polignac number, because 27638993 - 2¹² = 27634897 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (27688993) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 33380 + ... + 34197.

It is an arithmetic number, because the mean of its divisors is an integer number (6926745).

Almost surely, 2^27638993 is an apocalyptic number.

It is an amenable number.

27638993 is a deficient number, since it is larger than the sum of its proper divisors (67987).

27638993 is an equidigital number, since it uses as much as digits as its factorization.

27638993 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 67986.

The product of its digits is 489888, while the sum is 47.

The square root of 27638993 is about 5257.2800001522. The cubic root of 27638993 is about 302.3482124452.

The spelling of 27638993 in words is "twenty-seven million, six hundred thirty-eight thousand, nine hundred ninety-three".