42528509 has 4 divisors (see below), whose sum is σ = 45030204. Its totient is φ = 40026816.

The previous prime is 42528491. The next prime is 42528511. The reversal of 42528509 is 90582524.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 39413284 + 3115225 = 6278^2 + 1765^2 .

It is a cyclic number.

It is not a de Polignac number, because 42528509 - 2⁸ = 42528253 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (42528539) 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, 1250822 + ... + 1250855.

It is an arithmetic number, because the mean of its divisors is an integer number (11257551).

Almost surely, 2^42528509 is an apocalyptic number.

It is an amenable number.

42528509 is a deficient number, since it is larger than the sum of its proper divisors (2501695).

42528509 is a wasteful number, since it uses less digits than its factorization.

42528509 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2501694.

The product of its (nonzero) digits is 28800, while the sum is 35.

The square root of 42528509 is about 6521.3885791294. The cubic root of 42528509 is about 349.0546160725.

The spelling of 42528509 in words is "forty-two million, five hundred twenty-eight thousand, five hundred nine".