66543640768810 has 32 divisors (see below), whose sum is σ = 126828969840720. Its totient is φ = 25050811149312.

The previous prime is 66543640768807. The next prime is 66543640768823. The reversal of 66543640768810 is 1886704634566.

It can be written as a sum of positive squares in 8 ways, for example, as 44192673131049 + 22350967637761 = 6647757^2 + 4727681^2 .

It is a super-2 number, since 2×66543640768810² (a number of 28 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2438109 + ... + 11791168.

Almost surely, 2^{66543640768810} is an apocalyptic number.

66543640768810 is a deficient number, since it is larger than the sum of its proper divisors (60285329071910).

66543640768810 is a wasteful number, since it uses less digits than its factorization.

66543640768810 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14256810.

The product of its (nonzero) digits is 139345920, while the sum is 64.

The spelling of 66543640768810 in words is "sixty-six trillion, five hundred forty-three billion, six hundred forty million, seven hundred sixty-eight thousand, eight hundred ten".