51808621 has 8 divisors (see below), whose sum is σ = 54005600. Its totient is φ = 49653648.

The previous prime is 51808619. The next prime is 51808643. The reversal of 51808621 is 12680815.

51808621 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 a cyclic number.

It is not a de Polignac number, because 51808621 - 2¹ = 51808619 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 (51808321) 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, 7971 + ... + 12928.

It is an arithmetic number, because the mean of its divisors is an integer number (6750700).

Almost surely, 2^51808621 is an apocalyptic number.

It is an amenable number.

51808621 is a deficient number, since it is larger than the sum of its proper divisors (2196979).

51808621 is a wasteful number, since it uses less digits than its factorization.

51808621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21003.

The product of its (nonzero) digits is 3840, while the sum is 31.

The square root of 51808621 is about 7197.8205729234. The cubic root of 51808621 is about 372.7926526217.

The spelling of 51808621 in words is "fifty-one million, eight hundred eight thousand, six hundred twenty-one".