51815228208 has 80 divisors (see below), whose sum is σ = 137086940160. Its totient is φ = 16856908288.

The previous prime is 51815228189. The next prime is 51815228219. The reversal of 51815228208 is 80282251815.

It is a self number, because there is not a number n which added to its sum of digits gives 51815228208.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 777916 + ... + 841892.

It is an arithmetic number, because the mean of its divisors is an integer number (1713586752).

Almost surely, 2^51815228208 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 51815228208, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (68543470080).

51815228208 is an abundant number, since it is smaller than the sum of its proper divisors (85271711952).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

51815228208 is a wasteful number, since it uses less digits than its factorization.

51815228208 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 64394 (or 64388 counting only the distinct ones).

The product of its (nonzero) digits is 102400, while the sum is 42.

The spelling of 51815228208 in words is "fifty-one billion, eight hundred fifteen million, two hundred twenty-eight thousand, two hundred eight".