51186221 has 8 divisors (see below), whose sum is σ = 51919224. Its totient is φ = 50457600.

The previous prime is 51186203. The next prime is 51186227. The reversal of 51186221 is 12268115.

It can be written as a sum of positive squares in 4 ways, for example, as 9066121 + 42120100 = 3011^2 + 6490^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 51186221 - 2¹⁴ = 51169837 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51186227) 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 7 ways as a sum of consecutive naturals, for example, 27521 + ... + 29321.

It is an arithmetic number, because the mean of its divisors is an integer number (6489903).

Almost surely, 2^51186221 is an apocalyptic number.

It is an amenable number.

51186221 is a deficient number, since it is larger than the sum of its proper divisors (733003).

51186221 is a wasteful number, since it uses less digits than its factorization.

51186221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2191.

The product of its digits is 960, while the sum is 26.

The square root of 51186221 is about 7154.4546263150. The cubic root of 51186221 is about 371.2937930480.

The spelling of 51186221 in words is "fifty-one million, one hundred eighty-six thousand, two hundred twenty-one".