201166661 has 16 divisors (see below), whose sum is σ = 224804160. Its totient is φ = 178894080.

The previous prime is 201166639. The next prime is 201166663. The reversal of 201166661 is 166661102.

It is a cyclic number.

It is not a de Polignac number, because 201166661 - 2⁶ = 201166597 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (201166663) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 189071 + ... + 190131.

It is an arithmetic number, because the mean of its divisors is an integer number (14050260).

Almost surely, 2^201166661 is an apocalyptic number.

It is an amenable number.

201166661 is a deficient number, since it is larger than the sum of its proper divisors (23637499).

201166661 is a wasteful number, since it uses less digits than its factorization.

201166661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1684.

The product of its (nonzero) digits is 2592, while the sum is 29.

The square root of 201166661 is about 14183.3233411637. The cubic root of 201166661 is about 585.9384562250.

The spelling of 201166661 in words is "two hundred one million, one hundred sixty-six thousand, six hundred sixty-one".