27861989 has 4 divisors (see below), whose sum is σ = 28149324. Its totient is φ = 27574656.

The previous prime is 27861971. The next prime is 27862007. The reversal of 27861989 is 98916872.

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

It is an interprime number because it is at equal distance from previous prime (27861971) and next prime (27862007).

It can be written as a sum of positive squares in 2 ways, for example, as 19509889 + 8352100 = 4417^2 + 2890^2 .

It is a cyclic number.

It is not a de Polignac number, because 27861989 - 2¹⁶ = 27796453 is a prime.

It is a super-2 number, since 2×27861989² = 1552580862072242, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (27861949) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 143522 + ... + 143715.

It is an arithmetic number, because the mean of its divisors is an integer number (7037331).

Almost surely, 2^27861989 is an apocalyptic number.

It is an amenable number.

27861989 is a deficient number, since it is larger than the sum of its proper divisors (287335).

27861989 is an equidigital number, since it uses as much as digits as its factorization.

27861989 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 287334.

The product of its digits is 435456, while the sum is 50.

The square root of 27861989 is about 5278.4456992566. The cubic root of 27861989 is about 303.1591672826.

The spelling of 27861989 in words is "twenty-seven million, eight hundred sixty-one thousand, nine hundred eighty-nine".