156561666 has 16 divisors (see below), whose sum is σ = 313593984. Its totient is φ = 52108784.

The previous prime is 156561649. The next prime is 156561703. The reversal of 156561666 is 666165651.

It is a Curzon number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 15210 + ... + 23333.

It is an arithmetic number, because the mean of its divisors is an integer number (19599624).

Almost surely, 2^156561666 is an apocalyptic number.

156561666 is an abundant number, since it is smaller than the sum of its proper divisors (157032318).

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

156561666 is a wasteful number, since it uses less digits than its factorization.

156561666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 39225.

The product of its digits is 194400, while the sum is 42.

The square root of 156561666 is about 12512.4604295079. The cubic root of 156561666 is about 538.9665488217.

The spelling of 156561666 in words is "one hundred fifty-six million, five hundred sixty-one thousand, six hundred sixty-six".