66503339981764 has 81 divisors (see below), whose sum is σ = 136002149347239. Its totient is φ = 28371425080320.

The previous prime is 66503339981723. The next prime is 66503339981777. The reversal of 66503339981764 is 46718993330566.

The square root of 66503339981764 is 8154958.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in 4 ways, for example, as 39941768002500 + 26561571979264 = 6319950^2 + 5153792^2 .

It is a junction number, because it is equal to n+sod(n) for n = 66503339981693 and 66503339981702.

It is an unprimeable number.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 27514827084 + ... + 27514829500.

Almost surely, 2^{66503339981764} is an apocalyptic number.

66503339981764 is the 8154958-th square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 66503339981764

66503339981764 is an abundant number, since it is smaller than the sum of its proper divisors (69498809365475).

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

66503339981764 is an frugal number, since it uses more digits than its factorization.

66503339981764 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5334 (or 2667 counting only the distinct ones).

The product of its (nonzero) digits is 529079040, while the sum is 70.

The spelling of 66503339981764 in words is "sixty-six trillion, five hundred three billion, three hundred thirty-nine million, nine hundred eighty-one thousand, seven hundred sixty-four".