201221650709 has 4 divisors (see below), whose sum is σ = 201908414316. Its totient is φ = 200534887104.

The previous prime is 201221650639. The next prime is 201221650733. The reversal of 201221650709 is 907056122102.

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

It can be written as a sum of positive squares in 2 ways, for example, as 170953306225 + 30268344484 = 413465^2 + 173978^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-201221650709 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (201221650759) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 343381364 + ... + 343381949.

It is an arithmetic number, because the mean of its divisors is an integer number (50477103579).

Almost surely, 2^201221650709 is an apocalyptic number.

It is an amenable number.

201221650709 is a deficient number, since it is larger than the sum of its proper divisors (686763607).

201221650709 is an equidigital number, since it uses as much as digits as its factorization.

201221650709 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 686763606.

The product of its (nonzero) digits is 15120, while the sum is 35.

The spelling of 201221650709 in words is "two hundred one billion, two hundred twenty-one million, six hundred fifty thousand, seven hundred nine".