51666365 has 4 divisors (see below), whose sum is σ = 61999644. Its totient is φ = 41333088.

The previous prime is 51666347. The next prime is 51666379. The reversal of 51666365 is 56366615.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 24019801 + 27646564 = 4901^2 + 5258^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-51666365 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5166632 + ... + 5166641.

It is an arithmetic number, because the mean of its divisors is an integer number (15499911).

Almost surely, 2^51666365 is an apocalyptic number.

It is an amenable number.

51666365 is a deficient number, since it is larger than the sum of its proper divisors (10333279).

51666365 is a wasteful number, since it uses less digits than its factorization.

51666365 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10333278.

The product of its digits is 97200, while the sum is 38.

The square root of 51666365 is about 7187.9319000669. The cubic root of 51666365 is about 372.4511354307.

The spelling of 51666365 in words is "fifty-one million, six hundred sixty-six thousand, three hundred sixty-five".