661242166 has 64 divisors (see below), whose sum is σ = 1186617600. Its totient is φ = 273401856.

The previous prime is 661242163. The next prime is 661242167.

661242166 is nontrivially palindromic in base 10.

661242166 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (34).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (661242163) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1012296 + ... + 1012948.

It is an arithmetic number, because the mean of its divisors is an integer number (18540900).

Almost surely, 2^661242166 is an apocalyptic number.

661242166 is a deficient number, since it is larger than the sum of its proper divisors (525375434).

661242166 is a wasteful number, since it uses less digits than its factorization.

661242166 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 793.

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

The square root of 661242166 is about 25714.6294159570. The cubic root of 661242166 is about 871.2046402998.

The spelling of 661242166 in words is "six hundred sixty-one million, two hundred forty-two thousand, one hundred sixty-six".