642844039 has 2 divisors, whose sum is σ = 642844040. Its totient is φ = 642844038.

The previous prime is 642844009. The next prime is 642844079. The reversal of 642844039 is 930448246.

It is an a-pointer prime, because the next prime (642844079) can be obtained adding 642844039 to its sum of digits (40).

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 642844039 - 2¹⁵ = 642811271 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 642843992 and 642844010.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (642844009) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 321422019 + 321422020.

It is an arithmetic number, because the mean of its divisors is an integer number (321422020).

Almost surely, 2^642844039 is an apocalyptic number.

642844039 is a deficient number, since it is larger than the sum of its proper divisors (1).

642844039 is an equidigital number, since it uses as much as digits as its factorization.

642844039 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 165888, while the sum is 40.

The square root of 642844039 is about 25354.3692289909. The cubic root of 642844039 is about 863.0485098545.

The spelling of 642844039 in words is "six hundred forty-two million, eight hundred forty-four thousand, thirty-nine".