66862200578761 has 9 divisors (see below), whose sum is σ = 77778544807911. Its totient is φ = 57310408577352.

The previous prime is 66862200578759. The next prime is 66862200578827. The reversal of 66862200578761 is 16787500226866.

It is a happy number.

The square root of 66862200578761 is 8176931.

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

It can be written as a sum of positive squares in only one way, i.e., 49333274775225 + 17528925803536 = 7023765^2 + 4186756^2 .

It is not a de Polignac number, because 66862200578761 - 2¹ = 66862200578759 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 66862200578693 and 66862200578702.

It is not an unprimeable number, because it can be changed into a prime (66862200578741) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 56654451 + ... + 57822583.

Almost surely, 2^{66862200578761} is an apocalyptic number.

66862200578761 is the 8176931-st square number.

66862200578761 is the 4088466-th centered octagonal number.

It is an amenable number.

66862200578761 is a deficient number, since it is larger than the sum of its proper divisors (10916344229150).

66862200578761 is an frugal number, since it uses more digits than its factorization.

66862200578761 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2336280 (or 1168140 counting only the distinct ones).

The product of its (nonzero) digits is 81285120, while the sum is 64.

The spelling of 66862200578761 in words is "sixty-six trillion, eight hundred sixty-two billion, two hundred million, five hundred seventy-eight thousand, seven hundred sixty-one".