547991 has 4 divisors (see below), whose sum is σ = 549672. Its totient is φ = 546312.

The previous prime is 547957. The next prime is 547999. The reversal of 547991 is 199745.

547991 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 547991 - 2¹⁰ = 546967 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 (547999) 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, 176 + ... + 1061.

It is an arithmetic number, because the mean of its divisors is an integer number (137418).

2⁵⁴⁷⁹⁹¹ is an apocalyptic number.

547991 is a deficient number, since it is larger than the sum of its proper divisors (1681).

547991 is a wasteful number, since it uses less digits than its factorization.

547991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1680.

The product of its digits is 11340, while the sum is 35.

The square root of 547991 is about 740.2641420466. The cubic root of 547991 is about 81.8322467777.

The spelling of 547991 in words is "five hundred forty-seven thousand, nine hundred ninety-one".