42040221 has 4 divisors (see below), whose sum is σ = 56053632. Its totient is φ = 28026812.

The previous prime is 42040199. The next prime is 42040249. The reversal of 42040221 is 12204024.

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 42040221 - 2⁶ = 42040157 is a prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 42040221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (42040121) 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, 7006701 + ... + 7006706.

It is an arithmetic number, because the mean of its divisors is an integer number (14013408).

Almost surely, 2^42040221 is an apocalyptic number.

It is an amenable number.

42040221 is a deficient number, since it is larger than the sum of its proper divisors (14013411).

42040221 is a wasteful number, since it uses less digits than its factorization.

42040221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14013410.

The product of its (nonzero) digits is 128, while the sum is 15.

The square root of 42040221 is about 6483.8430733632. The cubic root of 42040221 is about 347.7135888238.

Adding to 42040221 its reverse (12204024), we get a palindrome (54244245).

The spelling of 42040221 in words is "forty-two million, forty thousand, two hundred twenty-one".