42518221 has 4 divisors (see below), whose sum is σ = 43422912. Its totient is φ = 41613532.

The previous prime is 42518213. The next prime is 42518227. The reversal of 42518221 is 12281524.

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 42518221 - 2³ = 42518213 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (42518227) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 452275 + ... + 452368.

It is an arithmetic number, because the mean of its divisors is an integer number (10855728).

Almost surely, 2^42518221 is an apocalyptic number.

It is an amenable number.

42518221 is a deficient number, since it is larger than the sum of its proper divisors (904691).

42518221 is an equidigital number, since it uses as much as digits as its factorization.

42518221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 904690.

The product of its digits is 1280, while the sum is 25.

The square root of 42518221 is about 6520.5997423550. The cubic root of 42518221 is about 349.0264673977.

Adding to 42518221 its reverse (12281524), we get a palindrome (54799745).

The spelling of 42518221 in words is "forty-two million, five hundred eighteen thousand, two hundred twenty-one".