42784639 has 2 divisors, whose sum is σ = 42784640. Its totient is φ = 42784638.

The previous prime is 42784633. The next prime is 42784673. The reversal of 42784639 is 93648724.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 42784639 - 2⁹ = 42784127 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 42784595 and 42784604.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (42784633) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21392319 + 21392320.

It is an arithmetic number, because the mean of its divisors is an integer number (21392320).

Almost surely, 2^42784639 is an apocalyptic number.

42784639 is a deficient number, since it is larger than the sum of its proper divisors (1).

42784639 is an equidigital number, since it uses as much as digits as its factorization.

42784639 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 290304, while the sum is 43.

The square root of 42784639 is about 6540.9967894809. The cubic root of 42784639 is about 349.7539467908.

The spelling of 42784639 in words is "forty-two million, seven hundred eighty-four thousand, six hundred thirty-nine".