51211321 has 6 divisors (see below), whose sum is σ = 59572410. Its totient is φ = 43895376.

The previous prime is 51211319. The next prime is 51211331. The reversal of 51211321 is 12311215.

51211321 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in only one way, i.e., 35569296 + 15642025 = 5964^2 + 3955^2 .

It is not a de Polignac number, because 51211321 - 2¹ = 51211319 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 51211295 and 51211304.

It is not an unprimeable number, because it can be changed into a prime (51211331) 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 5 ways as a sum of consecutive naturals, for example, 522516 + ... + 522613.

It is an arithmetic number, because the mean of its divisors is an integer number (9928735).

Almost surely, 2^51211321 is an apocalyptic number.

It is an amenable number.

51211321 is a deficient number, since it is larger than the sum of its proper divisors (8361089).

51211321 is a wasteful number, since it uses less digits than its factorization.

51211321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1045143 (or 1045136 counting only the distinct ones).

The product of its digits is 60, while the sum is 16.

The square root of 51211321 is about 7156.2085631988. The cubic root of 51211321 is about 371.3544731238.

Adding to 51211321 its reverse (12311215), we get a palindrome (63522536).

The spelling of 51211321 in words is "fifty-one million, two hundred eleven thousand, three hundred twenty-one".