166066209540 has 288 divisors, whose sum is σ = 655339216896. Its totient is φ = 33006885120.

The previous prime is 166066209509. The next prime is 166066209541. The reversal of 166066209540 is 45902660661.

166066209540 is a `hidden beast` number, since 16 + 6 + 0 + 6 + 620 + 9 + 5 + 4 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is not an unprimeable number, because it can be changed into a prime (166066209541) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 58309 + ... + 579251.

It is an arithmetic number, because the mean of its divisors is an integer number (2275483392).

Almost surely, 2^166066209540 is an apocalyptic number.

166066209540 is a gapful number since it is divisible by the number (10) 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 166066209540, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (327669608448).

166066209540 is an abundant number, since it is smaller than the sum of its proper divisors (489273007356).

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

166066209540 is a wasteful number, since it uses less digits than its factorization.

166066209540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 520999 (or 520994 counting only the distinct ones).

The product of its (nonzero) digits is 466560, while the sum is 45.

The spelling of 166066209540 in words is "one hundred sixty-six billion, sixty-six million, two hundred nine thousand, five hundred forty".