42840945 has 36 divisors (see below), whose sum is σ = 86385780. Its totient is φ = 19583424.

The previous prime is 42840937. The next prime is 42840947. The reversal of 42840945 is 54904824.

It can be written as a sum of positive squares in 2 ways, for example, as 5239521 + 37601424 = 2289^2 + 6132^2 .

It is not a de Polignac number, because 42840945 - 2³ = 42840937 is a prime.

It is not an unprimeable number, because it can be changed into a prime (42840947) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 7510 + ... + 11919.

It is an arithmetic number, because the mean of its divisors is an integer number (2399605).

Almost surely, 2^42840945 is an apocalyptic number.

42840945 is a gapful number since it is divisible by the number (45) formed by its first and last digit.

It is an amenable number.

42840945 is an abundant number, since it is smaller than the sum of its proper divisors (43544835).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

42840945 is a wasteful number, since it uses less digits than its factorization.

42840945 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19454 (or 19444 counting only the distinct ones).

The product of its (nonzero) digits is 46080, while the sum is 36.

The square root of 42840945 is about 6545.2994583900. The cubic root of 42840945 is about 349.9073087879.

The spelling of 42840945 in words is "forty-two million, eight hundred forty thousand, nine hundred forty-five".