27538721 has 4 divisors (see below), whose sum is σ = 31472832. Its totient is φ = 23604612.

The previous prime is 27538711. The next prime is 27538723. The reversal of 27538721 is 12783572.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-27538721 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (27538723) 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, 1967045 + ... + 1967058.

It is an arithmetic number, because the mean of its divisors is an integer number (7868208).

Almost surely, 2^27538721 is an apocalyptic number.

It is an amenable number.

27538721 is a deficient number, since it is larger than the sum of its proper divisors (3934111).

27538721 is an equidigital number, since it uses as much as digits as its factorization.

27538721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3934110.

The product of its digits is 23520, while the sum is 35.

The square root of 27538721 is about 5247.7348446735. The cubic root of 27538721 is about 301.9821378848.

The spelling of 27538721 in words is "twenty-seven million, five hundred thirty-eight thousand, seven hundred twenty-one".