42111021221 has 2 divisors, whose sum is σ = 42111021222. Its totient is φ = 42111021220.

The previous prime is 42111021217. The next prime is 42111021259. The reversal of 42111021221 is 12212011124.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 22653561121 + 19457460100 = 150511^2 + 139490^2 .

It is a cyclic number.

It is not a de Polignac number, because 42111021221 - 2² = 42111021217 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 42111021221.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (42111011221) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21055510610 + 21055510611.

It is an arithmetic number, because the mean of its divisors is an integer number (21055510611).

Almost surely, 2^42111021221 is an apocalyptic number.

It is an amenable number.

42111021221 is a deficient number, since it is larger than the sum of its proper divisors (1).

42111021221 is an equidigital number, since it uses as much as digits as its factorization.

42111021221 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 64, while the sum is 17.

Adding to 42111021221 its reverse (12212011124), we get a palindrome (54323032345).

The spelling of 42111021221 in words is "forty-two billion, one hundred eleven million, twenty-one thousand, two hundred twenty-one".