51694321 has 4 divisors (see below), whose sum is σ = 59079232. Its totient is φ = 44309412.

The previous prime is 51694289. The next prime is 51694333. The reversal of 51694321 is 12349615.

51694321 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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, and also an emirpimes, since its reverse is a distinct semiprime: 12349615 = 5 ⋅2469923.

It is not a de Polignac number, because 51694321 - 2⁵ = 51694289 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (51694351) 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 3 ways as a sum of consecutive naturals, for example, 3692445 + ... + 3692458.

It is an arithmetic number, because the mean of its divisors is an integer number (14769808).

Almost surely, 2^51694321 is an apocalyptic number.

It is an amenable number.

51694321 is a deficient number, since it is larger than the sum of its proper divisors (7384911).

51694321 is an equidigital number, since it uses as much as digits as its factorization.

51694321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7384910.

The product of its digits is 6480, while the sum is 31.

The square root of 51694321 is about 7189.8762854447. The cubic root of 51694321 is about 372.5182994779.

The spelling of 51694321 in words is "fifty-one million, six hundred ninety-four thousand, three hundred twenty-one".