820222032221 has 16 divisors (see below), whose sum is σ = 849803393904. Its totient is φ = 791048208384.

The previous prime is 820222032211. The next prime is 820222032281. The reversal of 820222032221 is 122230222028.

It can be written as a sum of positive squares in 8 ways, for example, as 1712800996 + 818509231225 = 41386^2 + 904715^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-820222032221 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 (820222032211) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3291221 + ... + 3531653.

It is an arithmetic number, because the mean of its divisors is an integer number (53112712119).

Almost surely, 2^820222032221 is an apocalyptic number.

It is an amenable number.

820222032221 is a deficient number, since it is larger than the sum of its proper divisors (29581361683).

820222032221 is a wasteful number, since it uses less digits than its factorization.

820222032221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 241280.

The product of its (nonzero) digits is 3072, while the sum is 26.

Adding to 820222032221 its reverse (122230222028), we get a palindrome (942452254249).

The spelling of 820222032221 in words is "eight hundred twenty billion, two hundred twenty-two million, thirty-two thousand, two hundred twenty-one".