51666646 has 16 divisors (see below), whose sum is σ = 80437248. Its totient is φ = 24863400.

The previous prime is 51666617. The next prime is 51666649. The reversal of 51666646 is 64666615.

It is a junction number, because it is equal to n+sod(n) for n = 51666599 and 51666608.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51666649) 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, 9661 + ... + 14023.

It is an arithmetic number, because the mean of its divisors is an integer number (5027328).

Almost surely, 2^51666646 is an apocalyptic number.

51666646 is a deficient number, since it is larger than the sum of its proper divisors (28770602).

51666646 is a wasteful number, since it uses less digits than its factorization.

51666646 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4587.

The product of its digits is 155520, while the sum is 40.

The square root of 51666646 is about 7187.9514466919. The cubic root of 51666646 is about 372.4518106513.

The spelling of 51666646 in words is "fifty-one million, six hundred sixty-six thousand, six hundred forty-six".