51808807 has 4 divisors (see below), whose sum is σ = 51883416. Its totient is φ = 51734200.

The previous prime is 51808739. The next prime is 51808817. The reversal of 51808807 is 70880815.

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 51808807 - 2²³ = 43420199 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 (51808817) 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, 36253 + ... + 37654.

It is an arithmetic number, because the mean of its divisors is an integer number (12970854).

Almost surely, 2^51808807 is an apocalyptic number.

51808807 is a deficient number, since it is larger than the sum of its proper divisors (74609).

51808807 is an equidigital number, since it uses as much as digits as its factorization.

51808807 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 74608.

The product of its (nonzero) digits is 17920, while the sum is 37.

The square root of 51808807 is about 7197.8334934896. The cubic root of 51808807 is about 372.7930987466.

The spelling of 51808807 in words is "fifty-one million, eight hundred eight thousand, eight hundred seven".