549918191 has 4 divisors (see below), whose sum is σ = 550040400. Its totient is φ = 549795984.

The previous prime is 549918163. The next prime is 549918221. The reversal of 549918191 is 191819945.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 191819945 = 5 ⋅38363989.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-549918191 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 (549918101) 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, 54086 + ... + 63443.

It is an arithmetic number, because the mean of its divisors is an integer number (137510100).

Almost surely, 2^549918191 is an apocalyptic number.

549918191 is a deficient number, since it is larger than the sum of its proper divisors (122209).

549918191 is a wasteful number, since it uses less digits than its factorization.

549918191 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 122208.

The product of its digits is 116640, while the sum is 47.

The square root of 549918191 is about 23450.3345605132. The cubic root of 549918191 is about 819.2806456446.

The spelling of 549918191 in words is "five hundred forty-nine million, nine hundred eighteen thousand, one hundred ninety-one".