51687839 has 8 divisors (see below), whose sum is σ = 60512928. Its totient is φ = 43223040.

The previous prime is 51687821. The next prime is 51687851. The reversal of 51687839 is 93878615.

It is a happy number.

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

It is not a de Polignac number, because 51687839 - 2²⁰ = 50639263 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 51687793 and 51687802.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51687899) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 89762 + ... + 90335.

It is an arithmetic number, because the mean of its divisors is an integer number (7564116).

Almost surely, 2^51687839 is an apocalyptic number.

51687839 is a deficient number, since it is larger than the sum of its proper divisors (8825089).

51687839 is a wasteful number, since it uses less digits than its factorization.

51687839 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 180145.

The product of its digits is 362880, while the sum is 47.

The square root of 51687839 is about 7189.4254986056. The cubic root of 51687839 is about 372.5027286859.

The spelling of 51687839 in words is "fifty-one million, six hundred eighty-seven thousand, eight hundred thirty-nine".