51689779 has 4 divisors (see below), whose sum is σ = 52344160. Its totient is φ = 51035400.

The previous prime is 51689773. The next prime is 51689821. The reversal of 51689779 is 97798615.

It is a happy number.

51689779 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 51689779 - 2¹⁷ = 51558707 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (51689773) 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, 327072 + ... + 327229.

It is an arithmetic number, because the mean of its divisors is an integer number (13086040).

Almost surely, 2^51689779 is an apocalyptic number.

51689779 is a deficient number, since it is larger than the sum of its proper divisors (654381).

51689779 is an equidigital number, since it uses as much as digits as its factorization.

51689779 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 654380.

The product of its digits is 952560, while the sum is 52.

The square root of 51689779 is about 7189.5604177168. The cubic root of 51689779 is about 372.5073890101.

The spelling of 51689779 in words is "fifty-one million, six hundred eighty-nine thousand, seven hundred seventy-nine".