42643739 has 2 divisors, whose sum is σ = 42643740. Its totient is φ = 42643738.

The previous prime is 42643729. The next prime is 42643793. The reversal of 42643739 is 93734624.

Together with next prime (42643793) it forms an Ormiston pair, because they use the same digits, order apart.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 42643739 - 2⁸ = 42643483 is a prime.

It is not a weakly prime, because it can be changed into another prime (42643729) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21321869 + 21321870.

It is an arithmetic number, because the mean of its divisors is an integer number (21321870).

Almost surely, 2^42643739 is an apocalyptic number.

42643739 is a deficient number, since it is larger than the sum of its proper divisors (1).

42643739 is an equidigital number, since it uses as much as digits as its factorization.

42643739 is an evil number, because the sum of its binary digits is even.

The product of its digits is 108864, while the sum is 38.

The square root of 42643739 is about 6530.2173776988. The cubic root of 42643739 is about 349.3695835494.

The spelling of 42643739 in words is "forty-two million, six hundred forty-three thousand, seven hundred thirty-nine".