42131221 has 4 divisors (see below), whose sum is σ = 45961344. Its totient is φ = 38301100.

The previous prime is 42131183. The next prime is 42131267. The reversal of 42131221 is 12213124.

42131221 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 42131221 - 2⁷ = 42131093 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 42131195 and 42131204.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (42131281) 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 3 ways as a sum of consecutive naturals, for example, 1915045 + ... + 1915066.

It is an arithmetic number, because the mean of its divisors is an integer number (11490336).

Almost surely, 2^42131221 is an apocalyptic number.

It is an amenable number.

42131221 is a deficient number, since it is larger than the sum of its proper divisors (3830123).

42131221 is a wasteful number, since it uses less digits than its factorization.

42131221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3830122.

The product of its digits is 96, while the sum is 16.

The square root of 42131221 is about 6490.8567231144. The cubic root of 42131221 is about 347.9642942403.

Adding to 42131221 its reverse (12213124), we get a palindrome (54344345).

The spelling of 42131221 in words is "forty-two million, one hundred thirty-one thousand, two hundred twenty-one".