42245821 has 8 divisors (see below), whose sum is σ = 42723000. Its totient is φ = 41771520.

The previous prime is 42245813. The next prime is 42245843. The reversal of 42245821 is 12854224.

It can be written as a sum of positive squares in 4 ways, for example, as 1144900 + 41100921 = 1070^2 + 6411^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 42245821 - 2³ = 42245813 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 42245821.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (42245891) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 41365 + ... + 42373.

It is an arithmetic number, because the mean of its divisors is an integer number (5340375).

Almost surely, 2^42245821 is an apocalyptic number.

It is an amenable number.

42245821 is a deficient number, since it is larger than the sum of its proper divisors (477179).

42245821 is a wasteful number, since it uses less digits than its factorization.

42245821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1439.

The product of its digits is 5120, while the sum is 28.

The square root of 42245821 is about 6499.6785305121. The cubic root of 42245821 is about 348.2795047174.

The spelling of 42245821 in words is "forty-two million, two hundred forty-five thousand, eight hundred twenty-one".