66609886374144 has 675 divisors, whose sum is σ = 210996786676137. Its totient is φ = 20900721973248.

The previous prime is 66609886374127. The next prime is 66609886374169. The reversal of 66609886374144 is 44147368890666.

The square root of 66609886374144 is 8161488.

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., 19524379449600 + 47085506924544 = 4418640^2 + 6861888^2 .

It is a super-3 number, since 3×66609886374144³ (a number of 42 digits) contains 333 as substring.

It is a Harshad number since it is a multiple of its sum of digits (72).

It is an unprimeable number.

It is a polite number, since it can be written in 74 ways as a sum of consecutive naturals, for example, 424266792114 + ... + 424266792270.

Almost surely, 2^{66609886374144} is an apocalyptic number.

66609886374144 is a gapful number since it is divisible by the number (64) formed by its first and last digit.

66609886374144 is the 8161488-th square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 66609886374144

66609886374144 is an abundant number, since it is smaller than the sum of its proper divisors (144386900301993).

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

66609886374144 is an frugal number, since it uses more digits than its factorization.

66609886374144 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 418 (or 181 counting only the distinct ones).

The product of its (nonzero) digits is 1003290624, while the sum is 72.

The spelling of 66609886374144 in words is "sixty-six trillion, six hundred nine billion, eight hundred eighty-six million, three hundred seventy-four thousand, one hundred forty-four".