42565221 has 18 divisors (see below), whose sum is σ = 62848422. Its totient is φ = 27760080.

The previous prime is 42565219. The next prime is 42565223. The reversal of 42565221 is 12256524.

42565221 is a `hidden beast` number, since 4 + 2 + 5 + 652 + 2 + 1 = 666.

It is an interprime number because it is at equal distance from previous prime (42565219) and next prime (42565223).

It can be written as a sum of positive squares in only one way, i.e., 42068196 + 497025 = 6486^2 + 705^2 .

It is not a de Polignac number, because 42565221 - 2¹ = 42565219 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (42565223) by changing a digit.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 18811 + ... + 20951.

It is an arithmetic number, because the mean of its divisors is an integer number (3491579).

Almost surely, 2^42565221 is an apocalyptic number.

It is an amenable number.

42565221 is a deficient number, since it is larger than the sum of its proper divisors (20283201).

42565221 is a wasteful number, since it uses less digits than its factorization.

42565221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2241 (or 2191 counting only the distinct ones).

The product of its digits is 4800, while the sum is 27.

The square root of 42565221 is about 6524.2027099102. The cubic root of 42565221 is about 349.1550256396.

The spelling of 42565221 in words is "forty-two million, five hundred sixty-five thousand, two hundred twenty-one".