66021706644480 has 440 divisors, whose sum is σ = 236621985518688. Its totient is φ = 17602996764672.

The previous prime is 66021706644389. The next prime is 66021706644497. The reversal of 66021706644480 is 8444660712066.

It is a happy number.

66021706644480 is a `hidden beast` number, since 6 + 60 + 2 + 1 + 7 + 0 + 66 + 44 + 480 = 666.

It is a super-3 number, since 3×66021706644480³ (a number of 42 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a hoax number, since the sum of its digits (54) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 5091510957 + ... + 5091523923.

Almost surely, 2^{66021706644480} is an apocalyptic number.

66021706644480 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 66021706644480, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (118310992759344).

66021706644480 is an abundant number, since it is smaller than the sum of its proper divisors (170600278874208).

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

66021706644480 is a wasteful number, since it uses less digits than its factorization.

66021706644480 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25281 (or 25254 counting only the distinct ones).

The product of its (nonzero) digits is 9289728, while the sum is 54.

The spelling of 66021706644480 in words is "sixty-six trillion, twenty-one billion, seven hundred six million, six hundred forty-four thousand, four hundred eighty".