27988781 has 8 divisors (see below), whose sum is σ = 28502880. Its totient is φ = 27477648.

The previous prime is 27988777. The next prime is 27988787. The reversal of 27988781 is 18788972.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 27988781 - 2² = 27988777 is a prime.

It is a super-2 number, since 2×27988781² = 1566743723731922, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (27988787) 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 7 ways as a sum of consecutive naturals, for example, 27575 + ... + 28571.

It is an arithmetic number, because the mean of its divisors is an integer number (3562860).

Almost surely, 2^27988781 is an apocalyptic number.

It is an amenable number.

27988781 is a deficient number, since it is larger than the sum of its proper divisors (514099).

27988781 is an equidigital number, since it uses as much as digits as its factorization.

27988781 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1483.

The product of its digits is 451584, while the sum is 50.

The square root of 27988781 is about 5290.4424200628. The cubic root of 27988781 is about 303.6183352319.

The spelling of 27988781 in words is "twenty-seven million, nine hundred eighty-eight thousand, seven hundred eighty-one".