166203261 has 48 divisors (see below), whose sum is σ = 282597120. Its totient is φ = 92171520.

The previous prime is 166203251. The next prime is 166203287. The reversal of 166203261 is 162302661.

166203261 is a `hidden beast` number, since 1 + 6 + 620 + 32 + 6 + 1 = 666.

It is not a de Polignac number, because 166203261 - 2⁶ = 166203197 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (166203211) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 326275 + ... + 326783.

It is an arithmetic number, because the mean of its divisors is an integer number (5887440).

Almost surely, 2^166203261 is an apocalyptic number.

It is an amenable number.

166203261 is a deficient number, since it is larger than the sum of its proper divisors (116393859).

166203261 is a wasteful number, since it uses less digits than its factorization.

166203261 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 666 (or 663 counting only the distinct ones).

The product of its (nonzero) digits is 2592, while the sum is 27.

The square root of 166203261 is about 12891.9843701426. The cubic root of 166203261 is about 549.8106907704.

It can be divided in two parts, 166203 and 261, that added together give a square (166464 = 408²).

The spelling of 166203261 in words is "one hundred sixty-six million, two hundred three thousand, two hundred sixty-one".