42206509 has 4 divisors (see below), whose sum is σ = 42267420. Its totient is φ = 42145600.

The previous prime is 42206501. The next prime is 42206533. The reversal of 42206509 is 90560224.

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 13616100 + 28590409 = 3690^2 + 5347^2 .

It is a cyclic number.

It is not a de Polignac number, because 42206509 - 2³ = 42206501 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 (42206501) 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, 29404 + ... + 30805.

It is an arithmetic number, because the mean of its divisors is an integer number (10566855).

Almost surely, 2^42206509 is an apocalyptic number.

It is an amenable number.

42206509 is a deficient number, since it is larger than the sum of its proper divisors (60911).

42206509 is an equidigital number, since it uses as much as digits as its factorization.

42206509 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 60910.

The product of its (nonzero) digits is 4320, while the sum is 28.

The square root of 42206509 is about 6496.6536770864. The cubic root of 42206509 is about 348.1714402771.

The spelling of 42206509 in words is "forty-two million, two hundred six thousand, five hundred nine".