42551209 has 8 divisors (see below), whose sum is σ = 44364672. Its totient is φ = 40775280.

The previous prime is 42551191. The next prime is 42551237. The reversal of 42551209 is 90215524.

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 42551209 - 2¹¹ = 42549161 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (42551269) 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, 7057 + ... + 11614.

It is an arithmetic number, because the mean of its divisors is an integer number (5545584).

Almost surely, 2^42551209 is an apocalyptic number.

It is an amenable number.

42551209 is a deficient number, since it is larger than the sum of its proper divisors (1813463).

42551209 is a wasteful number, since it uses less digits than its factorization.

42551209 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18767.

The product of its (nonzero) digits is 3600, while the sum is 28.

The square root of 42551209 is about 6523.1287738324. The cubic root of 42551209 is about 349.1167087771.

The spelling of 42551209 in words is "forty-two million, five hundred fifty-one thousand, two hundred nine".