27663721 has 8 divisors (see below), whose sum is σ = 28481544. Its totient is φ = 26856960.

The previous prime is 27663719. The next prime is 27663731. The reversal of 27663721 is 12736672.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 4044121 + 23619600 = 2011^2 + 4860^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 27663721 - 2¹ = 27663719 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (27663731) 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 7 ways as a sum of consecutive naturals, for example, 2451 + ... + 7831.

It is an arithmetic number, because the mean of its divisors is an integer number (3560193).

Almost surely, 2^27663721 is an apocalyptic number.

It is an amenable number.

27663721 is a deficient number, since it is larger than the sum of its proper divisors (817823).

27663721 is an equidigital number, since it uses as much as digits as its factorization.

27663721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5531.

The product of its digits is 21168, while the sum is 34.

The square root of 27663721 is about 5259.6312608395. The cubic root of 27663721 is about 302.4383536698.

The spelling of 27663721 in words is "twenty-seven million, six hundred sixty-three thousand, seven hundred twenty-one".