51178609 has 6 divisors (see below), whose sum is σ = 54014370. Its totient is φ = 48484656.

The previous prime is 51178607. The next prime is 51178637. The reversal of 51178609 is 90687115.

51178609 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in only one way, i.e., 47568609 + 3610000 = 6897^2 + 1900^2 .

It is not a de Polignac number, because 51178609 - 2¹ = 51178607 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (51178601) 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 5 ways as a sum of consecutive naturals, for example, 70524 + ... + 71245.

It is an arithmetic number, because the mean of its divisors is an integer number (9002395).

Almost surely, 2^51178609 is an apocalyptic number.

It is an amenable number.

51178609 is a deficient number, since it is larger than the sum of its proper divisors (2835761).

51178609 is a wasteful number, since it uses less digits than its factorization.

51178609 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 141807 (or 141788 counting only the distinct ones).

The product of its (nonzero) digits is 15120, while the sum is 37.

The square root of 51178609 is about 7153.9226302777. The cubic root of 51178609 is about 371.2753868675.

The spelling of 51178609 in words is "fifty-one million, one hundred seventy-eight thousand, six hundred nine".