51512321 has 4 divisors (see below), whose sum is σ = 58871232. Its totient is φ = 44153412.

The previous prime is 51512299. The next prime is 51512333. The reversal of 51512321 is 12321515.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 51512321 - 2¹⁰ = 51511297 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 51512293 and 51512302.

It is not an unprimeable number, because it can be changed into a prime (51512371) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3679445 + ... + 3679458.

It is an arithmetic number, because the mean of its divisors is an integer number (14717808).

Almost surely, 2^51512321 is an apocalyptic number.

It is an amenable number.

51512321 is a deficient number, since it is larger than the sum of its proper divisors (7358911).

51512321 is an equidigital number, since it uses as much as digits as its factorization.

51512321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7358910.

The product of its digits is 300, while the sum is 20.

The square root of 51512321 is about 7177.2084406125. The cubic root of 51512321 is about 372.0806108307.

Adding to 51512321 its reverse (12321515), we get a palindrome (63833836).

The spelling of 51512321 in words is "fifty-one million, five hundred twelve thousand, three hundred twenty-one".