51781373280 has 1152 divisors, whose sum is σ = 234751426560. Its totient is φ = 10555453440.

The previous prime is 51781373207. The next prime is 51781373359. The reversal of 51781373280 is 8237318715.

51781373280 is a `hidden beast` number, since 517 + 81 + 37 + 3 + 28 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 85306737 + ... + 85307343.

It is an arithmetic number, because the mean of its divisors is an integer number (203777280).

Almost surely, 2^51781373280 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 51781373280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (117375713280).

51781373280 is an abundant number, since it is smaller than the sum of its proper divisors (182970053280).

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

51781373280 is a wasteful number, since it uses less digits than its factorization.

51781373280 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 689 (or 668 counting only the distinct ones).

The product of its (nonzero) digits is 282240, while the sum is 45.

The spelling of 51781373280 in words is "fifty-one billion, seven hundred eighty-one million, three hundred seventy-three thousand, two hundred eighty".