11605206221 has 16 divisors (see below), whose sum is σ = 13696650240. Its totient is φ = 9622419840.

The previous prime is 11605206203. The next prime is 11605206229. The reversal of 11605206221 is 12260250611.

It is a de Polignac number, because none of the positive numbers 2^k-11605206221 is a prime.

It is a super-2 number, since 2×11605206221² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11605206229) by changing a digit.

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 15 ways as a sum of consecutive naturals, for example, 582395 + ... + 601991.

It is an arithmetic number, because the mean of its divisors is an integer number (856040640).

Almost surely, 2^11605206221 is an apocalyptic number.

It is an amenable number.

11605206221 is a deficient number, since it is larger than the sum of its proper divisors (2091444019).

11605206221 is a wasteful number, since it uses less digits than its factorization.

11605206221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22364.

The product of its (nonzero) digits is 1440, while the sum is 26.

Adding to 11605206221 its reverse (12260250611), we get a palindrome (23865456832).

The spelling of 11605206221 in words is "eleven billion, six hundred five million, two hundred six thousand, two hundred twenty-one".