51432421 has 4 divisors (see below), whose sum is σ = 51475500. Its totient is φ = 51389344.

The previous prime is 51432391. The next prime is 51432431. The reversal of 51432421 is 12423415.

51432421 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 an emirpimes, since its reverse is a distinct semiprime: 12423415 = 5 ⋅2484683.

It can be written as a sum of positive squares in 2 ways, for example, as 47803396 + 3629025 = 6914^2 + 1905^2 .

It is a cyclic number.

It is not a de Polignac number, because 51432421 - 2¹¹ = 51430373 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 51432392 and 51432401.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51432431) 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, 19696 + ... + 22153.

It is an arithmetic number, because the mean of its divisors is an integer number (12868875).

Almost surely, 2^51432421 is an apocalyptic number.

It is an amenable number.

51432421 is a deficient number, since it is larger than the sum of its proper divisors (43079).

51432421 is a wasteful number, since it uses less digits than its factorization.

51432421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 43078.

The product of its digits is 960, while the sum is 22.

The square root of 51432421 is about 7171.6400495284. The cubic root of 51432421 is about 371.8881350350. Note that the first 3 decimals are identical.

Adding to 51432421 its reverse (12423415), we get a palindrome (63855836).

The spelling of 51432421 in words is "fifty-one million, four hundred thirty-two thousand, four hundred twenty-one".