51666521 has 8 divisors (see below), whose sum is σ = 53289984. Its totient is φ = 50062320.

The previous prime is 51666499. The next prime is 51666539. The reversal of 51666521 is 12566615.

51666521 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It is a de Polignac number, because none of the positive numbers 2^k-51666521 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (51666821) by changing a digit.

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 in 7 ways as a sum of consecutive naturals, for example, 731 + ... + 10191.

It is an arithmetic number, because the mean of its divisors is an integer number (6661248).

Almost surely, 2^51666521 is an apocalyptic number.

It is an amenable number.

51666521 is a deficient number, since it is larger than the sum of its proper divisors (1623463).

51666521 is a wasteful number, since it uses less digits than its factorization.

51666521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9631.

The product of its digits is 10800, while the sum is 32.

The square root of 51666521 is about 7187.9427515806. The cubic root of 51666521 is about 372.4515102865.

The spelling of 51666521 in words is "fifty-one million, six hundred sixty-six thousand, five hundred twenty-one".