42121545 has 16 divisors (see below), whose sum is σ = 68064192. Its totient is φ = 22241600.

The previous prime is 42121501. The next prime is 42121549. The reversal of 42121545 is 54512124.

It is not a de Polignac number, because 42121545 - 2⁶ = 42121481 is a prime.

It is not an unprimeable number, because it can be changed into a prime (42121549) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 12387 + ... + 15416.

It is an arithmetic number, because the mean of its divisors is an integer number (4254012).

Almost surely, 2^42121545 is an apocalyptic number.

It is an amenable number.

42121545 is a deficient number, since it is larger than the sum of its proper divisors (25942647).

42121545 is a wasteful number, since it uses less digits than its factorization.

42121545 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27912.

The product of its digits is 1600, while the sum is 24.

The square root of 42121545 is about 6490.1113241608. Note that the first 3 decimals coincide. The cubic root of 42121545 is about 347.9376539784.

Adding to 42121545 its reverse (54512124), we get a palindrome (96633669).

The spelling of 42121545 in words is "forty-two million, one hundred twenty-one thousand, five hundred forty-five".