51685216 has 24 divisors (see below), whose sum is σ = 111006504. Its totient is φ = 23493120.

The previous prime is 51685213. The next prime is 51685217. The reversal of 51685216 is 61258615.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51685213) 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 3 ways as a sum of consecutive naturals, for example, 73065 + ... + 73768.

It is an arithmetic number, because the mean of its divisors is an integer number (4625271).

Almost surely, 2^51685216 is an apocalyptic number.

It is an amenable number.

51685216 is an abundant number, since it is smaller than the sum of its proper divisors (59321288).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

51685216 is a wasteful number, since it uses less digits than its factorization.

51685216 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 146854 (or 146846 counting only the distinct ones).

The product of its digits is 14400, while the sum is 34.

The square root of 51685216 is about 7189.2430755956. The cubic root of 51685216 is about 372.4964274540.

The spelling of 51685216 in words is "fifty-one million, six hundred eighty-five thousand, two hundred sixteen".