51171787 has 4 divisors (see below), whose sum is σ = 51650136. Its totient is φ = 50693440.

The previous prime is 51171773. The next prime is 51171797. The reversal of 51171787 is 78717115.

It is a happy number.

51171787 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, and also an emirpimes, since its reverse is a distinct semiprime: 78717115 = 5 ⋅15743423.

It is a cyclic number.

It is not a de Polignac number, because 51171787 - 2¹¹ = 51169739 is a prime.

It is a pancake number, because a pancake can be divided into 51171787 parts by 10116 straight cuts.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (51171797) 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 3 ways as a sum of consecutive naturals, for example, 239014 + ... + 239227.

It is an arithmetic number, because the mean of its divisors is an integer number (12912534).

Almost surely, 2^51171787 is an apocalyptic number.

51171787 is a deficient number, since it is larger than the sum of its proper divisors (478349).

51171787 is a wasteful number, since it uses less digits than its factorization.

51171787 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 478348.

The product of its digits is 13720, while the sum is 37.

The square root of 51171787 is about 7153.4458130330. The cubic root of 51171787 is about 371.2588893940.

The spelling of 51171787 in words is "fifty-one million, one hundred seventy-one thousand, seven hundred eighty-seven".