27981137 has 4 divisors (see below), whose sum is σ = 28080996. Its totient is φ = 27881280.

The previous prime is 27981131. The next prime is 27981169. The reversal of 27981137 is 73118972.

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 21381376 + 6599761 = 4624^2 + 2569^2 .

It is a cyclic number.

It is not a de Polignac number, because 27981137 - 2⁶ = 27981073 is a prime.

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 27981137.

It is not an unprimeable number, because it can be changed into a prime (27981131) 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, 49508 + ... + 50069.

It is an arithmetic number, because the mean of its divisors is an integer number (7020249).

Almost surely, 2^27981137 is an apocalyptic number.

It is an amenable number.

27981137 is a deficient number, since it is larger than the sum of its proper divisors (99859).

27981137 is an equidigital number, since it uses as much as digits as its factorization.

27981137 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 99858.

The product of its digits is 21168, while the sum is 38.

The square root of 27981137 is about 5289.7199358756. The cubic root of 27981137 is about 303.5906923719.

The spelling of 27981137 in words is "twenty-seven million, nine hundred eighty-one thousand, one hundred thirty-seven".