201661606 has 4 divisors (see below), whose sum is σ = 302492412. Its totient is φ = 100830802.

The previous prime is 201661601. The next prime is 201661609. The reversal of 201661606 is 606166102.

It is a semiprime because it is the product of two primes.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (201661601) 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 as a sum of consecutive naturals, namely, 50415400 + ... + 50415403.

It is an arithmetic number, because the mean of its divisors is an integer number (75623103).

Almost surely, 2^201661606 is an apocalyptic number.

201661606 is a deficient number, since it is larger than the sum of its proper divisors (100830806).

201661606 is a wasteful number, since it uses less digits than its factorization.

201661606 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 100830805.

The product of its (nonzero) digits is 2592, while the sum is 28.

The square root of 201661606 is about 14200.7607542695. The cubic root of 201661606 is about 586.4186050236.

The spelling of 201661606 in words is "two hundred one million, six hundred sixty-one thousand, six hundred six".