201243666 has 64 divisors (see below), whose sum is σ = 450148608. Its totient is φ = 59574528.

The previous prime is 201243659. The next prime is 201243677. The reversal of 201243666 is 666342102.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 296920 + ... + 297596.

It is an arithmetic number, because the mean of its divisors is an integer number (7033572).

Almost surely, 2^201243666 is an apocalyptic number.

201243666 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 201243666, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (225074304).

201243666 is an abundant number, since it is smaller than the sum of its proper divisors (248904942).

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

201243666 is a wasteful number, since it uses less digits than its factorization.

201243666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 835.

The product of its (nonzero) digits is 10368, while the sum is 30.

The square root of 201243666 is about 14186.0377131883. The cubic root of 201243666 is about 586.0132108830.

Adding to 201243666 its reverse (666342102), we get a palindrome (867585768).

The spelling of 201243666 in words is "two hundred one million, two hundred forty-three thousand, six hundred sixty-six".