201918906 has 144 divisors (see below), whose sum is σ = 540277920. Its totient is φ = 56337120.

The previous prime is 201918901. The next prime is 201918907. The reversal of 201918906 is 609819102.

It is not an unprimeable number, because it can be changed into a prime (201918901) by changing a digit.

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 71 ways as a sum of consecutive naturals, for example, 1452585 + ... + 1452723.

It is an arithmetic number, because the mean of its divisors is an integer number (3751930).

Almost surely, 2^201918906 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 201918906, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (270138960).

201918906 is an abundant number, since it is smaller than the sum of its proper divisors (338359014).

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

201918906 is a wasteful number, since it uses less digits than its factorization.

201918906 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 231 (or 212 counting only the distinct ones).

The product of its (nonzero) digits is 7776, while the sum is 36.

The square root of 201918906 is about 14209.8172402040. The cubic root of 201918906 is about 586.6679028182.

The spelling of 201918906 in words is "two hundred one million, nine hundred eighteen thousand, nine hundred six".