51605666 has 8 divisors (see below), whose sum is σ = 88466880. Its totient is φ = 22116708.

The previous prime is 51605663. The next prime is 51605677. The reversal of 51605666 is 66650615.

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

It is not an unprimeable number, because it can be changed into a prime (51605663) 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, 1843046 + ... + 1843073.

It is an arithmetic number, because the mean of its divisors is an integer number (11058360).

Almost surely, 2^51605666 is an apocalyptic number.

51605666 is a deficient number, since it is larger than the sum of its proper divisors (36861214).

51605666 is a wasteful number, since it uses less digits than its factorization.

51605666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3686128.

The product of its (nonzero) digits is 32400, while the sum is 35.

The square root of 51605666 is about 7183.7083738136. The cubic root of 51605666 is about 372.3052231561.

The spelling of 51605666 in words is "fifty-one million, six hundred five thousand, six hundred sixty-six".