51685222 has 4 divisors (see below), whose sum is σ = 77527836. Its totient is φ = 25842610.

The previous prime is 51685217. The next prime is 51685243. The reversal of 51685222 is 22258615.

51685222 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 22258615 = 5 ⋅4451723.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12921304 + ... + 12921307.

It is an arithmetic number, because the mean of its divisors is an integer number (19381959).

Almost surely, 2^51685222 is an apocalyptic number.

51685222 is a deficient number, since it is larger than the sum of its proper divisors (25842614).

51685222 is a wasteful number, since it uses less digits than its factorization.

51685222 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25842613.

The product of its digits is 9600, while the sum is 31.

The square root of 51685222 is about 7189.2434928857. The cubic root of 51685222 is about 372.4964418680.

The spelling of 51685222 in words is "fifty-one million, six hundred eighty-five thousand, two hundred twenty-two".