42647221 has 4 divisors (see below), whose sum is σ = 44501472. Its totient is φ = 40792972.

The previous prime is 42647207. The next prime is 42647249. The reversal of 42647221 is 12274624.

It is a happy number.

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 42647221 - 2¹¹ = 42645173 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 42647221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (42647261) 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, 927091 + ... + 927136.

It is an arithmetic number, because the mean of its divisors is an integer number (11125368).

Almost surely, 2^42647221 is an apocalyptic number.

It is an amenable number.

42647221 is a deficient number, since it is larger than the sum of its proper divisors (1854251).

42647221 is a wasteful number, since it uses less digits than its factorization.

42647221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1854250.

The product of its digits is 5376, while the sum is 28.

The square root of 42647221 is about 6530.4839790019. The cubic root of 42647221 is about 349.3790923449.

The spelling of 42647221 in words is "forty-two million, six hundred forty-seven thousand, two hundred twenty-one".