27998191 has 16 divisors (see below), whose sum is σ = 31933440. Its totient is φ = 24334560.

The previous prime is 27998189. The next prime is 27998197. The reversal of 27998191 is 19189972.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 27998191 - 2¹ = 27998189 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 (27998197) 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, 64746 + ... + 65176.

It is an arithmetic number, because the mean of its divisors is an integer number (1995840).

Almost surely, 2^27998191 is an apocalyptic number.

27998191 is a deficient number, since it is larger than the sum of its proper divisors (3935249).

27998191 is a wasteful number, since it uses less digits than its factorization.

27998191 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 726.

The product of its digits is 81648, while the sum is 46.

The square root of 27998191 is about 5291.3316849353. The cubic root of 27998191 is about 303.6523575355.

The spelling of 27998191 in words is "twenty-seven million, nine hundred ninety-eight thousand, one hundred ninety-one".