51808705 has 8 divisors (see below), whose sum is σ = 66952872. Its totient is φ = 38258688.

The previous prime is 51808697. The next prime is 51808709. The reversal of 51808705 is 50780815.

It can be written as a sum of positive squares in 4 ways, for example, as 4460544 + 47348161 = 2112^2 + 6881^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 51808705 - 2³ = 51808697 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (51808709) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 398464 + ... + 398593.

It is an arithmetic number, because the mean of its divisors is an integer number (8369109).

Almost surely, 2^51808705 is an apocalyptic number.

It is an amenable number.

51808705 is a deficient number, since it is larger than the sum of its proper divisors (15144167).

51808705 is a wasteful number, since it uses less digits than its factorization.

51808705 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 797075.

The product of its (nonzero) digits is 11200, while the sum is 34.

The square root of 51808705 is about 7197.8264080207. The cubic root of 51808705 is about 372.7928540976.

The spelling of 51808705 in words is "fifty-one million, eight hundred eight thousand, seven hundred five".