42202121 has 4 divisors (see below), whose sum is σ = 45448452. Its totient is φ = 38955792.

The previous prime is 42202001. The next prime is 42202123. The reversal of 42202121 is 12120224.

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 24393721 + 17808400 = 4939^2 + 4220^2 .

It is a cyclic number.

It is not a de Polignac number, because 42202121 - 2¹⁰ = 42201097 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 42202096 and 42202105.

It is not an unprimeable number, because it can be changed into a prime (42202123) 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 3 ways as a sum of consecutive naturals, for example, 1623146 + ... + 1623171.

It is an arithmetic number, because the mean of its divisors is an integer number (11362113).

Almost surely, 2^42202121 is an apocalyptic number.

It is an amenable number.

42202121 is a deficient number, since it is larger than the sum of its proper divisors (3246331).

42202121 is a wasteful number, since it uses less digits than its factorization.

42202121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3246330.

The product of its (nonzero) digits is 64, while the sum is 14.

The square root of 42202121 is about 6496.3159559861. The cubic root of 42202121 is about 348.1593739769.

Adding to 42202121 its reverse (12120224), we get a palindrome (54322345).

The spelling of 42202121 in words is "forty-two million, two hundred two thousand, one hundred twenty-one".