42123122221 has 4 divisors (see below), whose sum is σ = 43019358912. Its totient is φ = 41226885532.

The previous prime is 42123122213. The next prime is 42123122263. The reversal of 42123122221 is 12222132124.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 42123122221 - 2³ = 42123122213 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 42123122192 and 42123122201.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (42123122521) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 448118275 + ... + 448118368.

It is an arithmetic number, because the mean of its divisors is an integer number (10754839728).

Almost surely, 2^42123122221 is an apocalyptic number.

It is an amenable number.

42123122221 is a deficient number, since it is larger than the sum of its proper divisors (896236691).

42123122221 is an equidigital number, since it uses as much as digits as its factorization.

42123122221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 896236690.

The product of its digits is 768, while the sum is 22.

Adding to 42123122221 its reverse (12222132124), we get a palindrome (54345254345).

The spelling of 42123122221 in words is "forty-two billion, one hundred twenty-three million, one hundred twenty-two thousand, two hundred twenty-one".