201660660 has 36 divisors (see below), whose sum is σ = 611704548. Its totient is φ = 53776128.

The previous prime is 201660649. The next prime is 201660677. The reversal of 201660660 is 66066102.

It can be written as a sum of positive squares in 2 ways, for example, as 98962704 + 102697956 = 9948^2 + 10134^2 .

It is a tau number, because it is divible by the number of its divisors (36).

It is a hoax number, since the sum of its digits (27) coincides with the sum of the digits of its distinct prime factors.

It is a congruent 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 11 ways as a sum of consecutive naturals, for example, 559989 + ... + 560348.

It is an arithmetic number, because the mean of its divisors is an integer number (16991793).

Almost surely, 2^201660660 is an apocalyptic number.

201660660 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

201660660 is an abundant number, since it is smaller than the sum of its proper divisors (410043888).

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

201660660 is a wasteful number, since it uses less digits than its factorization.

201660660 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1120352 (or 1120347 counting only the distinct ones).

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

The square root of 201660660 is about 14200.7274461557. The cubic root of 201660660 is about 586.4176880537.

The spelling of 201660660 in words is "two hundred one million, six hundred sixty thousand, six hundred sixty".