551778191 has 4 divisors (see below), whose sum is σ = 552174000. Its totient is φ = 551382384.

The previous prime is 551778179. The next prime is 551778223. The reversal of 551778191 is 191877155.

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 551778191 - 2¹⁰ = 551777167 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 (551778131) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 195806 + ... + 198603.

It is an arithmetic number, because the mean of its divisors is an integer number (138043500).

Almost surely, 2^551778191 is an apocalyptic number.

551778191 is a deficient number, since it is larger than the sum of its proper divisors (395809).

551778191 is a wasteful number, since it uses less digits than its factorization.

551778191 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 395808.

The product of its digits is 88200, while the sum is 44.

The square root of 551778191 is about 23489.9593656524. The cubic root of 551778191 is about 820.2032963124.

The spelling of 551778191 in words is "five hundred fifty-one million, seven hundred seventy-eight thousand, one hundred ninety-one".