201205721605 has 32 divisors (see below), whose sum is σ = 279181728000. Its totient is φ = 136349993472.

The previous prime is 201205721581. The next prime is 201205721617. The reversal of 201205721605 is 506127502102.

201205721605 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 201205721605 - 2¹⁵ = 201205688837 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 6522999 + ... + 6553771.

It is an arithmetic number, because the mean of its divisors is an integer number (8724429000).

Almost surely, 2^201205721605 is an apocalyptic number.

It is an amenable number.

201205721605 is a deficient number, since it is larger than the sum of its proper divisors (77976006395).

201205721605 is a wasteful number, since it uses less digits than its factorization.

201205721605 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 32973.

The product of its (nonzero) digits is 8400, while the sum is 31.

The spelling of 201205721605 in words is "two hundred one billion, two hundred five million, seven hundred twenty-one thousand, six hundred five".