51491779 has 12 divisors (see below), whose sum is σ = 54832176. Its totient is φ = 48263072.

The previous prime is 51491773. The next prime is 51491831. The reversal of 51491779 is 97719415.

51491779 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 51491779 - 2⁹ = 51491267 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (51491773) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 64209 + ... + 65005.

It is an arithmetic number, because the mean of its divisors is an integer number (4569348).

Almost surely, 2^51491779 is an apocalyptic number.

51491779 is a deficient number, since it is larger than the sum of its proper divisors (3340397).

51491779 is an equidigital number, since it uses as much as digits as its factorization.

51491779 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 926 (or 873 counting only the distinct ones).

The product of its digits is 79380, while the sum is 43.

The square root of 51491779 is about 7175.7772401322. Note that the first 3 decimals coincide. The cubic root of 51491779 is about 372.0311450202.

The spelling of 51491779 in words is "fifty-one million, four hundred ninety-one thousand, seven hundred seventy-nine".