27655991 has 16 divisors (see below), whose sum is σ = 32410368. Its totient is φ = 23318400.

The previous prime is 27655987. The next prime is 27655993. The reversal of 27655991 is 19955672.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 27655991 - 2² = 27655987 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (27655993) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 12236 + ... + 14318.

It is an arithmetic number, because the mean of its divisors is an integer number (2025648).

Almost surely, 2^27655991 is an apocalyptic number.

27655991 is a deficient number, since it is larger than the sum of its proper divisors (4754377).

27655991 is a wasteful number, since it uses less digits than its factorization.

27655991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2182.

The product of its digits is 170100, while the sum is 44.

The square root of 27655991 is about 5258.8963671097. The cubic root of 27655991 is about 302.4101811973.

The spelling of 27655991 in words is "twenty-seven million, six hundred fifty-five thousand, nine hundred ninety-one".