51519851885 has 4 divisors (see below), whose sum is σ = 61823822268. Its totient is φ = 41215881504.

The previous prime is 51519851863. The next prime is 51519851923. The reversal of 51519851885 is 58815891515.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 26099694916 + 25420156969 = 161554^2 + 159437^2 .

It is a cyclic number.

It is not a de Polignac number, because 51519851885 - 2⁸ = 51519851629 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 51519851885.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5151985184 + ... + 5151985193.

It is an arithmetic number, because the mean of its divisors is an integer number (15455955567).

Almost surely, 2^51519851885 is an apocalyptic number.

It is an amenable number.

51519851885 is a deficient number, since it is larger than the sum of its proper divisors (10303970383).

51519851885 is a wasteful number, since it uses less digits than its factorization.

51519851885 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10303970382.

The product of its digits is 2880000, while the sum is 56.

The spelling of 51519851885 in words is "fifty-one billion, five hundred nineteen million, eight hundred fifty-one thousand, eight hundred eighty-five".