51616421 has 4 divisors (see below), whose sum is σ = 51876000. Its totient is φ = 51356844.

The previous prime is 51616391. The next prime is 51616447. The reversal of 51616421 is 12461615.

51616421 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 51616421 - 2¹⁰ = 51615397 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51616321) 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, 129491 + ... + 129888.

It is an arithmetic number, because the mean of its divisors is an integer number (12969000).

Almost surely, 2^51616421 is an apocalyptic number.

It is an amenable number.

51616421 is a deficient number, since it is larger than the sum of its proper divisors (259579).

51616421 is a wasteful number, since it uses less digits than its factorization.

51616421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 259578.

The product of its digits is 1440, while the sum is 26.

The square root of 51616421 is about 7184.4569036219. The cubic root of 51616421 is about 372.3310850743.

The spelling of 51616421 in words is "fifty-one million, six hundred sixteen thousand, four hundred twenty-one".