20433213221 has 2 divisors, whose sum is σ = 20433213222. Its totient is φ = 20433213220.

The previous prime is 20433213217. The next prime is 20433213239. The reversal of 20433213221 is 12231233402.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20053392100 + 379821121 = 141610^2 + 19489^2 .

It is a cyclic number.

It is not a de Polignac number, because 20433213221 - 2² = 20433213217 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20433215221) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10216606610 + 10216606611.

It is an arithmetic number, because the mean of its divisors is an integer number (10216606611).

Almost surely, 2^20433213221 is an apocalyptic number.

It is an amenable number.

20433213221 is a deficient number, since it is larger than the sum of its proper divisors (1).

20433213221 is an equidigital number, since it uses as much as digits as its factorization.

20433213221 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1728, while the sum is 23.

Adding to 20433213221 its reverse (12231233402), we get a palindrome (32664446623).

The spelling of 20433213221 in words is "twenty billion, four hundred thirty-three million, two hundred thirteen thousand, two hundred twenty-one".