42639643 has 2 divisors, whose sum is σ = 42639644. Its totient is φ = 42639642.

The previous prime is 42639593. The next prime is 42639647. The reversal of 42639643 is 34693624.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-42639643 is a prime.

It is not a weakly prime, because it can be changed into another prime (42639647) 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 as a sum of consecutive naturals, namely, 21319821 + 21319822.

It is an arithmetic number, because the mean of its divisors is an integer number (21319822).

Almost surely, 2^42639643 is an apocalyptic number.

42639643 is a deficient number, since it is larger than the sum of its proper divisors (1).

42639643 is an equidigital number, since it uses as much as digits as its factorization.

42639643 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 93312, while the sum is 37.

The square root of 42639643 is about 6529.9037512049. The cubic root of 42639643 is about 349.3583973536.

The spelling of 42639643 in words is "forty-two million, six hundred thirty-nine thousand, six hundred forty-three".