42135111221 has 6 divisors (see below), whose sum is σ = 49014313110. Its totient is φ = 36115809576.

The previous prime is 42135111217. The next prime is 42135111223. The reversal of 42135111221 is 12211153124.

It can be written as a sum of positive squares in only one way, i.e., 21613116196 + 20521995025 = 147014^2 + 143255^2 .

It is not a de Polignac number, because 42135111221 - 2² = 42135111217 is a prime.

It is a super-2 number, since 2×42135111221² (a number of 22 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (42135111223) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 429950066 + ... + 429950163.

It is an arithmetic number, because the mean of its divisors is an integer number (8169052185).

Almost surely, 2^42135111221 is an apocalyptic number.

It is an amenable number.

42135111221 is a deficient number, since it is larger than the sum of its proper divisors (6879201889).

42135111221 is an equidigital number, since it uses as much as digits as its factorization.

42135111221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 859900243 (or 859900236 counting only the distinct ones).

The product of its digits is 480, while the sum is 23.

Adding to 42135111221 its reverse (12211153124), we get a palindrome (54346264345).

The spelling of 42135111221 in words is "forty-two billion, one hundred thirty-five million, one hundred eleven thousand, two hundred twenty-one".