201566646 has 24 divisors (see below), whose sum is σ = 451788480. Its totient is φ = 64871856.

The previous prime is 201566627. The next prime is 201566647. The reversal of 201566646 is 646665102.

It is a happy number.

It is a super-2 number, since 2×201566646² = 81258225559378632, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 201566646.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (201566647) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 192550 + ... + 193593.

It is an arithmetic number, because the mean of its divisors is an integer number (18824520).

Almost surely, 2^201566646 is an apocalyptic number.

201566646 is an abundant number, since it is smaller than the sum of its proper divisors (250221834).

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

201566646 is a wasteful number, since it uses less digits than its factorization.

201566646 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 386180 (or 386177 counting only the distinct ones).

The product of its (nonzero) digits is 51840, while the sum is 36.

The square root of 201566646 is about 14197.4168777281. The cubic root of 201566646 is about 586.3265447734.

The spelling of 201566646 in words is "two hundred one million, five hundred sixty-six thousand, six hundred forty-six".