42649909 has 8 divisors (see below), whose sum is σ = 43183800. Its totient is φ = 42119616.

The previous prime is 42649897. The next prime is 42649933. The reversal of 42649909 is 90994624.

It can be written as a sum of positive squares in 4 ways, for example, as 22372900 + 20277009 = 4730^2 + 4503^2 .

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 42649909 - 2⁵ = 42649877 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 (42649949) 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, 28627 + ... + 30079.

It is an arithmetic number, because the mean of its divisors is an integer number (5397975).

Almost surely, 2^42649909 is an apocalyptic number.

It is an amenable number.

42649909 is a deficient number, since it is larger than the sum of its proper divisors (533891).

42649909 is a wasteful number, since it uses less digits than its factorization.

42649909 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1799.

The product of its (nonzero) digits is 139968, while the sum is 43.

The square root of 42649909 is about 6530.6897798012. The cubic root of 42649909 is about 349.3864324970.

The spelling of 42649909 in words is "forty-two million, six hundred forty-nine thousand, nine hundred nine".