27760721 has 8 divisors (see below), whose sum is σ = 28265160. Its totient is φ = 27260928.

The previous prime is 27760697. The next prime is 27760727. The reversal of 27760721 is 12706772.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 9579025 + 18181696 = 3095^2 + 4264^2 .

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 27760721 - 2⁶ = 27760657 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (27760727) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 12245 + ... + 14333.

It is an arithmetic number, because the mean of its divisors is an integer number (3533145).

Almost surely, 2^27760721 is an apocalyptic number.

It is an amenable number.

27760721 is a deficient number, since it is larger than the sum of its proper divisors (504439).

27760721 is a wasteful number, since it uses less digits than its factorization.

27760721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2323.

The product of its (nonzero) digits is 8232, while the sum is 32.

The square root of 27760721 is about 5268.8443704478. The cubic root of 27760721 is about 302.7914310022.

The spelling of 27760721 in words is "twenty-seven million, seven hundred sixty thousand, seven hundred twenty-one".