201021606 has 48 divisors (see below), whose sum is σ = 447920928. Its totient is φ = 65116800.

The previous prime is 201021593. The next prime is 201021631. The reversal of 201021606 is 606120102.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a congruent number.

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 23 ways as a sum of consecutive naturals, for example, 310375 + ... + 311021.

It is an arithmetic number, because the mean of its divisors is an integer number (9331686).

Almost surely, 2^201021606 is an apocalyptic number.

201021606 is an abundant number, since it is smaller than the sum of its proper divisors (246899322).

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

201021606 is a wasteful number, since it uses less digits than its factorization.

201021606 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1117 (or 1114 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 18.

The square root of 201021606 is about 14178.2088431508. The cubic root of 201021606 is about 585.7975883841.

Adding to 201021606 its reverse (606120102), we get a palindrome (807141708).

The spelling of 201021606 in words is "two hundred one million, twenty-one thousand, six hundred six".