642112262221 has 2 divisors, whose sum is σ = 642112262222. Its totient is φ = 642112262220.

The previous prime is 642112262219. The next prime is 642112262243. The reversal of 642112262221 is 122262211246.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 494756085321 + 147356176900 = 703389^2 + 383870^2 .

It is a cyclic number.

It is not a de Polignac number, because 642112262221 - 2¹ = 642112262219 is a prime.

Together with 642112262219, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (642112262021) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 321056131110 + 321056131111.

It is an arithmetic number, because the mean of its divisors is an integer number (321056131111).

Almost surely, 2^642112262221 is an apocalyptic number.

It is an amenable number.

642112262221 is a deficient number, since it is larger than the sum of its proper divisors (1).

642112262221 is an equidigital number, since it uses as much as digits as its factorization.

642112262221 is an evil number, because the sum of its binary digits is even.

The product of its digits is 9216, while the sum is 31.

Adding to 642112262221 its reverse (122262211246), we get a palindrome (764374473467).

The spelling of 642112262221 in words is "six hundred forty-two billion, one hundred twelve million, two hundred sixty-two thousand, two hundred twenty-one".