51686807 has 4 divisors (see below), whose sum is σ = 51702360. Its totient is φ = 51671256.

The previous prime is 51686779. The next prime is 51686849. The reversal of 51686807 is 70868615.

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

It is a cyclic number.

It is not a de Polignac number, because 51686807 - 2¹⁰ = 51685783 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 (51688807) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 557 + ... + 10182.

It is an arithmetic number, because the mean of its divisors is an integer number (12925590).

Almost surely, 2^51686807 is an apocalyptic number.

51686807 is a deficient number, since it is larger than the sum of its proper divisors (15553).

51686807 is a wasteful number, since it uses less digits than its factorization.

51686807 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15552.

The product of its (nonzero) digits is 80640, while the sum is 41.

The square root of 51686807 is about 7189.3537261704. The cubic root of 51686807 is about 372.5002495381.

The spelling of 51686807 in words is "fifty-one million, six hundred eighty-six thousand, eight hundred seven".