51630421 has 4 divisors (see below), whose sum is σ = 51671232. Its totient is φ = 51589612.

The previous prime is 51630367. The next prime is 51630443. The reversal of 51630421 is 12403615.

51630421 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.

It is a cyclic number.

It is not a de Polignac number, because 51630421 - 2⁹ = 51629909 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 51630392 and 51630401.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51630451) 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, 18445 + ... + 21058.

It is an arithmetic number, because the mean of its divisors is an integer number (12917808).

Almost surely, 2^51630421 is an apocalyptic number.

It is an amenable number.

51630421 is a deficient number, since it is larger than the sum of its proper divisors (40811).

51630421 is a wasteful number, since it uses less digits than its factorization.

51630421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 40810.

The product of its (nonzero) digits is 720, while the sum is 22.

The square root of 51630421 is about 7185.4311631245. The cubic root of 51630421 is about 372.3647446726.

The spelling of 51630421 in words is "fifty-one million, six hundred thirty thousand, four hundred twenty-one".