51311321 has 8 divisors (see below), whose sum is σ = 56692224. Its totient is φ = 46192960.

The previous prime is 51311311. The next prime is 51311327. The reversal of 51311321 is 12311315.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-51311321 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (17).

It is a Duffinian number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 51311321.

It is not an unprimeable number, because it can be changed into a prime (51311327) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 65225 + ... + 66006.

It is an arithmetic number, because the mean of its divisors is an integer number (7086528).

Almost surely, 2^51311321 is an apocalyptic number.

It is an amenable number.

51311321 is a deficient number, since it is larger than the sum of its proper divisors (5380903).

51311321 is a wasteful number, since it uses less digits than its factorization.

51311321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 131271.

The product of its digits is 90, while the sum is 17.

The square root of 51311321 is about 7163.1920957071. The cubic root of 51311321 is about 371.5960297522.

Adding to 51311321 its reverse (12311315), we get a palindrome (63622636).

The spelling of 51311321 in words is "fifty-one million, three hundred eleven thousand, three hundred twenty-one".