27640221 has 16 divisors (see below), whose sum is σ = 43257984. Its totient is φ = 15367104.

The previous prime is 27640213. The next prime is 27640237. The reversal of 27640221 is 12204672.

It is not a de Polignac number, because 27640221 - 2³ = 27640213 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 27640191 and 27640200.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (27640211) by changing a digit.

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 15 ways as a sum of consecutive naturals, for example, 17010 + ... + 18563.

It is an arithmetic number, because the mean of its divisors is an integer number (2703624).

Almost surely, 2^27640221 is an apocalyptic number.

27640221 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

27640221 is a deficient number, since it is larger than the sum of its proper divisors (15617763).

27640221 is a wasteful number, since it uses less digits than its factorization.

27640221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 35620.

The product of its (nonzero) digits is 1344, while the sum is 24.

The square root of 27640221 is about 5257.3967892865. The cubic root of 27640221 is about 302.3526901542.

Adding to 27640221 its reverse (12204672), we get a palindrome (39844893).

The spelling of 27640221 in words is "twenty-seven million, six hundred forty thousand, two hundred twenty-one".