42121111 has 4 divisors (see below), whose sum is σ = 42238800. Its totient is φ = 42003424.

The previous prime is 42121099. The next prime is 42121147. The reversal of 42121111 is 11112124.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-42121111 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 42121091 and 42121100.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (42121151) 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, 58306 + ... + 59023.

It is an arithmetic number, because the mean of its divisors is an integer number (10559700).

Almost surely, 2^42121111 is an apocalyptic number.

42121111 is a deficient number, since it is larger than the sum of its proper divisors (117689).

42121111 is a wasteful number, since it uses less digits than its factorization.

42121111 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 117688.

The product of its digits is 16, while the sum is 13.

The square root of 42121111 is about 6490.0778885927. The cubic root of 42121111 is about 347.9364589806.

Adding to 42121111 its reverse (11112124), we get a palindrome (53233235).

The spelling of 42121111 in words is "forty-two million, one hundred twenty-one thousand, one hundred eleven".