27550991 has 4 divisors (see below), whose sum is σ = 29670312. Its totient is φ = 25431672.

The previous prime is 27550979. The next prime is 27550997. The reversal of 27550991 is 19905572.

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

It is a cyclic number.

It is not a de Polignac number, because 27550991 - 2⁶ = 27550927 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 (27550997) 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, 1059641 + ... + 1059666.

It is an arithmetic number, because the mean of its divisors is an integer number (7417578).

Almost surely, 2^27550991 is an apocalyptic number.

27550991 is a deficient number, since it is larger than the sum of its proper divisors (2119321).

27550991 is a wasteful number, since it uses less digits than its factorization.

27550991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2119320.

The product of its (nonzero) digits is 28350, while the sum is 38.

The square root of 27550991 is about 5248.9037903166. The cubic root of 27550991 is about 302.0269810550.

The spelling of 27550991 in words is "twenty-seven million, five hundred fifty thousand, nine hundred ninety-one".