51812221815 has 24 divisors (see below), whose sum is σ = 90094801680. Its totient is φ = 27544892544.

The previous prime is 51812221793. The next prime is 51812221819.

51812221815 is a `hidden beast` number, since 518 + 122 + 2 + 1 + 8 + 15 = 666.

51812221815 is nontrivially palindromic in base 10.

It is not a de Polignac number, because 51812221815 - 2⁷ = 51812221687 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 51812221815.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51812221819) 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 23 ways as a sum of consecutive naturals, for example, 1825185 + ... + 1853354.

It is an arithmetic number, because the mean of its divisors is an integer number (3753950070).

Almost surely, 2^51812221815 is an apocalyptic number.

51812221815 is a deficient number, since it is larger than the sum of its proper divisors (38282579865).

51812221815 is a wasteful number, since it uses less digits than its factorization.

51812221815 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3678863 (or 3678860 counting only the distinct ones).

The product of its digits is 12800, while the sum is 36.

The spelling of 51812221815 in words is "fifty-one billion, eight hundred twelve million, two hundred twenty-one thousand, eight hundred fifteen".