27971321 has 4 divisors (see below), whose sum is σ = 31967232. Its totient is φ = 23975412.

The previous prime is 27971311. The next prime is 27971329. The reversal of 27971321 is 12317972.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 27971321 - 2¹⁴ = 27954937 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (27971329) 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, 1997945 + ... + 1997958.

It is an arithmetic number, because the mean of its divisors is an integer number (7991808).

Almost surely, 2^27971321 is an apocalyptic number.

It is an amenable number.

27971321 is a deficient number, since it is larger than the sum of its proper divisors (3995911).

27971321 is an equidigital number, since it uses as much as digits as its factorization.

27971321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3995910.

The product of its digits is 5292, while the sum is 32.

The square root of 27971321 is about 5288.7920170867. The cubic root of 27971321 is about 303.5551875628. Note that the first 3 decimals are identical.

The spelling of 27971321 in words is "twenty-seven million, nine hundred seventy-one thousand, three hundred twenty-one".