66566506968900 has 243 divisors, whose sum is σ = 209466203903229. Its totient is φ = 17681816376000.

The previous prime is 66566506968893. The next prime is 66566506968919. The reversal of 66566506968900 is 986960566566.

The square root of 66566506968900 is 8158830.

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

66566506968900 is a `hidden beast` number, since 6 + 6 + 56 + 6 + 506 + 9 + 68 + 9 + 0 + 0 = 666.

It can be written as a sum of positive squares in only one way, i.e., 23963942508804 + 42602564460096 = 4895298^2 + 6527064^2 .

It is a super-2 number, since 2×66566506968900² (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 80 ways as a sum of consecutive naturals, for example, 105493671585 + ... + 105493672215.

Almost surely, 2^{66566506968900} is an apocalyptic number.

66566506968900 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

66566506968900 is the 8158830-th square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 66566506968900

66566506968900 is an abundant number, since it is smaller than the sum of its proper divisors (142899696934329).

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

66566506968900 is an equidigital number, since it uses as much as digits as its factorization.

66566506968900 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2144 (or 1072 counting only the distinct ones).

The product of its (nonzero) digits is 755827200, while the sum is 72.

The spelling of 66566506968900 in words is "sixty-six trillion, five hundred sixty-six billion, five hundred six million, nine hundred sixty-eight thousand, nine hundred".