166220120665 has 8 divisors (see below), whose sum is σ = 199641768768. Its totient is φ = 132857680560.

The previous prime is 166220120663. The next prime is 166220120683. The reversal of 166220120665 is 566021022661.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 166220120665 - 2¹ = 166220120663 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (166220120663) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 14795821 + ... + 14807050.

It is an arithmetic number, because the mean of its divisors is an integer number (24955221096).

Almost surely, 2^166220120665 is an apocalyptic number.

It is an amenable number.

166220120665 is a deficient number, since it is larger than the sum of its proper divisors (33421648103).

166220120665 is a wasteful number, since it uses less digits than its factorization.

166220120665 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 29603999.

The product of its (nonzero) digits is 51840, while the sum is 37.

The spelling of 166220120665 in words is "one hundred sixty-six billion, two hundred twenty million, one hundred twenty thousand, six hundred sixty-five".