42821784 has 40 divisors (see below), whose sum is σ = 119942460. Its totient is φ = 14273712.

The previous prime is 42821783. The next prime is 42821789. The reversal of 42821784 is 48712824.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (42821783) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 32394 + ... + 33689.

Almost surely, 2^42821784 is an apocalyptic number.

It is an amenable number.

42821784 is an abundant number, since it is smaller than the sum of its proper divisors (77120676).

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

42821784 is a wasteful number, since it uses less digits than its factorization.

42821784 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 66101 (or 66088 counting only the distinct ones).

The product of its digits is 28672, while the sum is 36.

The square root of 42821784 is about 6543.8355725064. The cubic root of 42821784 is about 349.8551346061.

The spelling of 42821784 in words is "forty-two million, eight hundred twenty-one thousand, seven hundred eighty-four".