42100022221 has 4 divisors (see below), whose sum is σ = 42102281212. Its totient is φ = 42097763232.

The previous prime is 42100022213. The next prime is 42100022257. The reversal of 42100022221 is 12222000124.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 12305464900 + 29794557321 = 110930^2 + 172611^2 .

It is a cyclic number.

It is not a de Polignac number, because 42100022221 - 2³ = 42100022213 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 42100022195 and 42100022204.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (42100022201) 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, 1101306 + ... + 1138891.

It is an arithmetic number, because the mean of its divisors is an integer number (10525570303).

Almost surely, 2^42100022221 is an apocalyptic number.

It is an amenable number.

42100022221 is a deficient number, since it is larger than the sum of its proper divisors (2258991).

42100022221 is a wasteful number, since it uses less digits than its factorization.

42100022221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2258990.

The product of its (nonzero) digits is 128, while the sum is 16.

Adding to 42100022221 its reverse (12222000124), we get a palindrome (54322022345).

The spelling of 42100022221 in words is "forty-two billion, one hundred million, twenty-two thousand, two hundred twenty-one".