27709921 has 8 divisors (see below), whose sum is σ = 28272744. Its totient is φ = 27150720.

The previous prime is 27709919. The next prime is 27709933. The reversal of 27709921 is 12990772.

It can be written as a sum of positive squares in 4 ways, for example, as 225 + 27709696 = 15^2 + 5264^2 .

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 27709921 - 2¹ = 27709919 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (27709321) 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, 18621 + ... + 20053.

It is an arithmetic number, because the mean of its divisors is an integer number (3534093).

Almost surely, 2^27709921 is an apocalyptic number.

It is an amenable number.

27709921 is a deficient number, since it is larger than the sum of its proper divisors (562823).

27709921 is a wasteful number, since it uses less digits than its factorization.

27709921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1811.

The product of its (nonzero) digits is 15876, while the sum is 37.

The square root of 27709921 is about 5264.0213715372. The cubic root of 27709921 is about 302.6066231610.

The spelling of 27709921 in words is "twenty-seven million, seven hundred nine thousand, nine hundred twenty-one".