51278325821 has 16 divisors (see below), whose sum is σ = 53819700480. Its totient is φ = 48763777920.

The previous prime is 51278325809. The next prime is 51278325827. The reversal of 51278325821 is 12852387215.

It is a cyclic number.

It is not a de Polignac number, because 51278325821 - 2¹⁸ = 51278063677 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51278325827) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2791256 + ... + 2809566.

It is an arithmetic number, because the mean of its divisors is an integer number (3363731280).

Almost surely, 2^51278325821 is an apocalyptic number.

It is an amenable number.

51278325821 is a deficient number, since it is larger than the sum of its proper divisors (2541374659).

51278325821 is a wasteful number, since it uses less digits than its factorization.

51278325821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19036.

The product of its digits is 268800, while the sum is 44.

The spelling of 51278325821 in words is "fifty-one billion, two hundred seventy-eight million, three hundred twenty-five thousand, eight hundred twenty-one".