27761221 has 8 divisors (see below), whose sum is σ = 29467800. Its totient is φ = 26062848.

The previous prime is 27761203. The next prime is 27761231. The reversal of 27761221 is 12216772.

It can be written as a sum of positive squares in 4 ways, for example, as 2208196 + 25553025 = 1486^2 + 5055^2 .

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 27761221 - 2⁵ = 27761189 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 27761221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (27761231) 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, 5815 + ... + 9451.

It is an arithmetic number, because the mean of its divisors is an integer number (3683475).

Almost surely, 2^27761221 is an apocalyptic number.

It is an amenable number.

27761221 is a deficient number, since it is larger than the sum of its proper divisors (1706579).

27761221 is a wasteful number, since it uses less digits than its factorization.

27761221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4103.

The product of its digits is 2352, while the sum is 28.

The square root of 27761221 is about 5268.8918189691. The cubic root of 27761221 is about 302.7932488561.

Adding to 27761221 its reverse (12216772), we get a palindrome (39977993).

The spelling of 27761221 in words is "twenty-seven million, seven hundred sixty-one thousand, two hundred twenty-one".