661022220166 has 16 divisors (see below), whose sum is σ = 1236197399040. Its totient is φ = 257541124680.

The previous prime is 661022220163. The next prime is 661022220203.

661022220166 is nontrivially palindromic in base 10.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (661022220163) 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, 2146175886 + ... + 2146176193.

It is an arithmetic number, because the mean of its divisors is an integer number (77262337440).

Almost surely, 2^661022220166 is an apocalyptic number.

661022220166 is a deficient number, since it is larger than the sum of its proper divisors (575175178874).

661022220166 is a wasteful number, since it uses less digits than its factorization.

661022220166 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4292352099.

The product of its (nonzero) digits is 20736, while the sum is 34.

It can be divided in two parts, 661022 and 220166, that added together give a palindrome (881188).

The spelling of 661022220166 in words is "six hundred sixty-one billion, twenty-two million, two hundred twenty thousand, one hundred sixty-six".