42649945 has 8 divisors (see below), whose sum is σ = 55116936. Its totient is φ = 31495296.

The previous prime is 42649933. The next prime is 42649949. The reversal of 42649945 is 54994624.

It can be written as a sum of positive squares in 4 ways, for example, as 1317904 + 41332041 = 1148^2 + 6429^2 .

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 42649945 - 2¹¹ = 42647897 is a prime.

It is a Duffinian 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, 328012 + ... + 328141.

It is an arithmetic number, because the mean of its divisors is an integer number (6889617).

Almost surely, 2^42649945 is an apocalyptic number.

It is an amenable number.

42649945 is a deficient number, since it is larger than the sum of its proper divisors (12466991).

42649945 is a wasteful number, since it uses less digits than its factorization.

42649945 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 656171.

The product of its digits is 311040, while the sum is 43.

The square root of 42649945 is about 6530.6925360179. The cubic root of 42649945 is about 349.3865308005.

The spelling of 42649945 in words is "forty-two million, six hundred forty-nine thousand, nine hundred forty-five".