51609791 has 4 divisors (see below), whose sum is σ = 51630000. Its totient is φ = 51589584.

The previous prime is 51609787. The next prime is 51609793. The reversal of 51609791 is 19790615.

51609791 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.

It is a cyclic number.

It is not a de Polignac number, because 51609791 - 2² = 51609787 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 (51609793) 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, 5606 + ... + 11603.

It is an arithmetic number, because the mean of its divisors is an integer number (12907500).

Almost surely, 2^51609791 is an apocalyptic number.

51609791 is a deficient number, since it is larger than the sum of its proper divisors (20209).

51609791 is a wasteful number, since it uses less digits than its factorization.

51609791 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20208.

The product of its (nonzero) digits is 17010, while the sum is 38.

The square root of 51609791 is about 7183.9954760565. The cubic root of 51609791 is about 372.3151427266.

The spelling of 51609791 in words is "fifty-one million, six hundred nine thousand, seven hundred ninety-one".