27252721 has 4 divisors (see below), whose sum is σ = 28192500. Its totient is φ = 26312944.

The previous prime is 27252671. The next prime is 27252727. The reversal of 27252721 is 12725272.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 19044496 + 8208225 = 4364^2 + 2865^2 .

It is a cyclic number.

It is not a de Polignac number, because 27252721 - 2⁹ = 27252209 is a prime.

It is an alternating number because its digits alternate between even and odd.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 27252721.

It is not an unprimeable number, because it can be changed into a prime (27252727) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 469846 + ... + 469903.

It is an arithmetic number, because the mean of its divisors is an integer number (7048125).

Almost surely, 2^27252721 is an apocalyptic number.

It is an amenable number.

27252721 is a deficient number, since it is larger than the sum of its proper divisors (939779).

27252721 is an equidigital number, since it uses as much as digits as its factorization.

27252721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 939778.

The product of its digits is 3920, while the sum is 28.

The square root of 27252721 is about 5220.4138724818. The cubic root of 27252721 is about 300.9330984523.

Adding to 27252721 its reverse (12725272), we get a palindrome (39977993).

The spelling of 27252721 in words is "twenty-seven million, two hundred fifty-two thousand, seven hundred twenty-one".