54999991 has 4 divisors (see below), whose sum is σ = 55118232. Its totient is φ = 54881752.

The previous prime is 54999943. The next prime is 55000013. The reversal of 54999991 is 19999945.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-54999991 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 (54999911) 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, 58420 + ... + 59353.

It is an arithmetic number, because the mean of its divisors is an integer number (13779558).

Almost surely, 2^54999991 is an apocalyptic number.

54999991 is a deficient number, since it is larger than the sum of its proper divisors (118241).

54999991 is a wasteful number, since it uses less digits than its factorization.

54999991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 118240.

The product of its digits is 1180980, while the sum is 55.

The square root of 54999991 is about 7416.1978803158. The cubic root of 54999991 is about 380.2952253328.

The spelling of 54999991 in words is "fifty-four million, nine hundred ninety-nine thousand, nine hundred ninety-one".