27981655 has 8 divisors (see below), whose sum is σ = 36160992. Its totient is φ = 20663328.

The previous prime is 27981647. The next prime is 27981697. The reversal of 27981655 is 55618972.

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 27981655 - 2³ = 27981647 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 215179 + ... + 215308.

It is an arithmetic number, because the mean of its divisors is an integer number (4520124).

Almost surely, 2^27981655 is an apocalyptic number.

27981655 is a deficient number, since it is larger than the sum of its proper divisors (8179337).

27981655 is a wasteful number, since it uses less digits than its factorization.

27981655 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 430505.

The product of its digits is 151200, while the sum is 43.

The square root of 27981655 is about 5289.7688985437. The cubic root of 27981655 is about 303.5925657650.

The spelling of 27981655 in words is "twenty-seven million, nine hundred eighty-one thousand, six hundred fifty-five".