51778813680 has 480 divisors, whose sum is σ = 206374291200. Its totient is φ = 11890644480.

The previous prime is 51778813663. The next prime is 51778813693. The reversal of 51778813680 is 8631887715.

It is a happy number.

51778813680 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a super-2 number, since 2×51778813680² (a number of 22 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 4960627 + ... + 4971053.

It is an arithmetic number, because the mean of its divisors is an integer number (429946440).

Almost surely, 2^51778813680 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 51778813680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (103187145600).

51778813680 is an abundant number, since it is smaller than the sum of its proper divisors (154595477520).

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

51778813680 is a wasteful number, since it uses less digits than its factorization.

51778813680 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10490 (or 10467 counting only the distinct ones).

The product of its (nonzero) digits is 2257920, while the sum is 54.

The spelling of 51778813680 in words is "fifty-one billion, seven hundred seventy-eight million, eight hundred thirteen thousand, six hundred eighty".