42780816 has 60 divisors (see below), whose sum is σ = 128942268. Its totient is φ = 13162752.

The previous prime is 42780811. The next prime is 42780863. The reversal of 42780816 is 61808724.

It can be written as a sum of positive squares in 2 ways, for example, as 6780816 + 36000000 = 2604^2 + 6000^2 .

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a nialpdrome in base 9.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (42780811) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 9555 + ... + 13298.

Almost surely, 2^42780816 is an apocalyptic number.

It is an amenable number.

42780816 is an abundant number, since it is smaller than the sum of its proper divisors (86161452).

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

42780816 is a wasteful number, since it uses less digits than its factorization.

42780816 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22880 (or 22871 counting only the distinct ones).

The product of its (nonzero) digits is 21504, while the sum is 36.

The square root of 42780816 is about 6540.7045492057. The cubic root of 42780816 is about 349.7435291175.

The spelling of 42780816 in words is "forty-two million, seven hundred eighty thousand, eight hundred sixteen".