51781786081356 has 24 divisors (see below), whose sum is σ = 120824340865200. Its totient is φ = 17260570597312.

The previous prime is 51781786081241. The next prime is 51781786081369. The reversal of 51781786081356 is 65318068718715.

It is a super-3 number, since 3×51781786081356³ (a number of 42 digits) contains 333 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6911470 + ... + 12301706.

It is an arithmetic number, because the mean of its divisors is an integer number (5034347536050).

Almost surely, 2^{51781786081356} is an apocalyptic number.

It is an amenable number.

51781786081356 is an abundant number, since it is smaller than the sum of its proper divisors (69042554783844).

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

51781786081356 is a wasteful number, since it uses less digits than its factorization.

51781786081356 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6190793 (or 6190791 counting only the distinct ones).

The product of its (nonzero) digits is 67737600, while the sum is 66.

The spelling of 51781786081356 in words is "fifty-one trillion, seven hundred eighty-one billion, seven hundred eighty-six million, eighty-one thousand, three hundred fifty-six".