27397921 has 4 divisors (see below), whose sum is σ = 27440532. Its totient is φ = 27355312.

The previous prime is 27397901. The next prime is 27397933. The reversal of 27397921 is 12979372.

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 10497600 + 16900321 = 3240^2 + 4111^2 .

It is a cyclic number.

It is not a de Polignac number, because 27397921 - 2¹³ = 27389729 is a prime.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (27397901) 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, 20326 + ... + 21631.

It is an arithmetic number, because the mean of its divisors is an integer number (6860133).

Almost surely, 2^27397921 is an apocalyptic number.

It is an amenable number.

27397921 is a deficient number, since it is larger than the sum of its proper divisors (42611).

27397921 is an equidigital number, since it uses as much as digits as its factorization.

27397921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 42610.

The product of its digits is 47628, while the sum is 40.

The square root of 27397921 is about 5234.3023412868. The cubic root of 27397921 is about 301.4666000787.

The spelling of 27397921 in words is "twenty-seven million, three hundred ninety-seven thousand, nine hundred twenty-one".