51507321 has 8 divisors (see below), whose sum is σ = 69284640. Its totient is φ = 34034112.

The previous prime is 51507317. The next prime is 51507341. The reversal of 51507321 is 12370515.

51507321 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It is not a de Polignac number, because 51507321 - 2² = 51507317 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 51507291 and 51507300.

It is not an unprimeable number, because it can be changed into a prime (51507301) 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 7 ways as a sum of consecutive naturals, for example, 75631 + ... + 76308.

It is an arithmetic number, because the mean of its divisors is an integer number (8660580).

Almost surely, 2^51507321 is an apocalyptic number.

It is an amenable number.

51507321 is a deficient number, since it is larger than the sum of its proper divisors (17777319).

51507321 is a wasteful number, since it uses less digits than its factorization.

51507321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 152055.

The product of its (nonzero) digits is 1050, while the sum is 24.

The square root of 51507321 is about 7176.8601073171. The cubic root of 51507321 is about 372.0685718776.

Adding to 51507321 its reverse (12370515), we get a palindrome (63877836).

The spelling of 51507321 in words is "fifty-one million, five hundred seven thousand, three hundred twenty-one".