51772221 has 24 divisors (see below), whose sum is σ = 77739480. Its totient is φ = 33161856.

The previous prime is 51772219. The next prime is 51772243. The reversal of 51772221 is 12227715.

It can be written as a sum of positive squares in 4 ways, for example, as 38266596 + 13505625 = 6186^2 + 3675^2 .

It is not a de Polignac number, because 51772221 - 2¹ = 51772219 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51772211) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 76135 + ... + 76811.

It is an arithmetic number, because the mean of its divisors is an integer number (3239145).

Almost surely, 2^51772221 is an apocalyptic number.

It is an amenable number.

51772221 is a deficient number, since it is larger than the sum of its proper divisors (25967259).

51772221 is a wasteful number, since it uses less digits than its factorization.

51772221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1005 (or 1002 counting only the distinct ones).

The product of its digits is 1960, while the sum is 27.

The square root of 51772221 is about 7195.2915854745. The cubic root of 51772221 is about 372.7053258958.

Adding to 51772221 its reverse (12227715), we get a palindrome (63999936).

The spelling of 51772221 in words is "fifty-one million, seven hundred seventy-two thousand, two hundred twenty-one".