42778944 has 168 divisors, whose sum is σ = 137297160. Its totient is φ = 12644352.

The previous prime is 42778913. The next prime is 42778961. The reversal of 42778944 is 44987724.

It can be written as a sum of positive squares in 4 ways, for example, as 10969344 + 31809600 = 3312^2 + 5640^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 42778944.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 217054 + ... + 217250.

It is an arithmetic number, because the mean of its divisors is an integer number (817245).

Almost surely, 2^42778944 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 42778944, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (68648580).

42778944 is an abundant number, since it is smaller than the sum of its proper divisors (94518216).

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

42778944 is a wasteful number, since it uses less digits than its factorization.

42778944 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 257 (or 244 counting only the distinct ones).

The product of its digits is 451584, while the sum is 45.

The square root of 42778944 is about 6540.5614437906. The cubic root of 42778944 is about 349.7384276920.

The spelling of 42778944 in words is "forty-two million, seven hundred seventy-eight thousand, nine hundred forty-four".