42020665 has 8 divisors (see below), whose sum is σ = 50469768. Its totient is φ = 33586560.

The previous prime is 42020639. The next prime is 42020669. The reversal of 42020665 is 56602024.

It can be written as a sum of positive squares in 4 ways, for example, as 7634169 + 34386496 = 2763^2 + 5864^2 .

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

It is not a de Polignac number, because 42020665 - 2¹¹ = 42018617 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (42020669) 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, 3805 + ... + 9925.

It is an arithmetic number, because the mean of its divisors is an integer number (6308721).

Almost surely, 2^42020665 is an apocalyptic number.

It is an amenable number.

42020665 is a deficient number, since it is larger than the sum of its proper divisors (8449103).

42020665 is a wasteful number, since it uses less digits than its factorization.

42020665 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7499.

The product of its (nonzero) digits is 2880, while the sum is 25.

The square root of 42020665 is about 6482.3348417063. The cubic root of 42020665 is about 347.6596647369.

Adding to 42020665 its reverse (56602024), we get a palindrome (98622689).

The spelling of 42020665 in words is "forty-two million, twenty thousand, six hundred sixty-five".