42028809 has 4 divisors (see below), whose sum is σ = 56038416. Its totient is φ = 28019204.

The previous prime is 42028787. The next prime is 42028849. The reversal of 42028809 is 90882024.

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 42028809 - 2⁹ = 42028297 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 42028809.

It is not an unprimeable number, because it can be changed into a prime (42028849) 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, 7004799 + ... + 7004804.

It is an arithmetic number, because the mean of its divisors is an integer number (14009604).

Almost surely, 2^42028809 is an apocalyptic number.

It is an amenable number.

42028809 is a deficient number, since it is larger than the sum of its proper divisors (14009607).

42028809 is a wasteful number, since it uses less digits than its factorization.

42028809 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14009606.

The product of its (nonzero) digits is 9216, while the sum is 33.

The square root of 42028809 is about 6482.9629799961. The cubic root of 42028809 is about 347.6821231901.

The spelling of 42028809 in words is "forty-two million, twenty-eight thousand, eight hundred nine".