42406221 has 16 divisors (see below), whose sum is σ = 66427200. Its totient is φ = 23723520.

The previous prime is 42406219. The next prime is 42406223. The reversal of 42406221 is 12260424.

It is an interprime number because it is at equal distance from previous prime (42406219) and next prime (42406223).

It is not a de Polignac number, because 42406221 - 2¹ = 42406219 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (42406223) 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, 48996 + ... + 49853.

It is an arithmetic number, because the mean of its divisors is an integer number (4151700).

Almost surely, 2^42406221 is an apocalyptic number.

It is an amenable number.

42406221 is a deficient number, since it is larger than the sum of its proper divisors (24020979).

42406221 is a wasteful number, since it uses less digits than its factorization.

42406221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 98876.

The product of its (nonzero) digits is 768, while the sum is 21.

The square root of 42406221 is about 6512.0059121595. The cubic root of 42406221 is about 348.7197335022.

Adding to 42406221 its reverse (12260424), we get a palindrome (54666645).

The spelling of 42406221 in words is "forty-two million, four hundred six thousand, two hundred twenty-one".