42121155 has 16 divisors (see below), whose sum is σ = 71358624. Its totient is φ = 21143040.

The previous prime is 42121153. The next prime is 42121181. The reversal of 42121155 is 55112124.

42121155 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 42121155 - 2¹ = 42121153 is a prime.

It is not an unprimeable number, because it can be changed into a prime (42121151) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 82336 + ... + 82845.

It is an arithmetic number, because the mean of its divisors is an integer number (4459914).

Almost surely, 2^42121155 is an apocalyptic number.

42121155 is a deficient number, since it is larger than the sum of its proper divisors (29237469).

42121155 is a wasteful number, since it uses less digits than its factorization.

42121155 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 165206.

The product of its digits is 400, while the sum is 21.

The square root of 42121155 is about 6490.0812783817. The cubic root of 42121155 is about 347.9365801328.

Adding to 42121155 its reverse (55112124), we get a palindrome (97233279).

The spelling of 42121155 in words is "forty-two million, one hundred twenty-one thousand, one hundred fifty-five".