642441539 has 2 divisors, whose sum is σ = 642441540. Its totient is φ = 642441538.

The previous prime is 642441533. The next prime is 642441559. The reversal of 642441539 is 935144246.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 642441539 - 2⁴ = 642441523 is a prime.

It is a super-2 number, since 2×642441539² = 825462262065377042, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (642441533) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 321220769 + 321220770.

It is an arithmetic number, because the mean of its divisors is an integer number (321220770).

Almost surely, 2^642441539 is an apocalyptic number.

642441539 is a deficient number, since it is larger than the sum of its proper divisors (1).

642441539 is an equidigital number, since it uses as much as digits as its factorization.

642441539 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 103680, while the sum is 38.

The square root of 642441539 is about 25346.4304981984. The cubic root of 642441539 is about 862.8683471557.

The spelling of 642441539 in words is "six hundred forty-two million, four hundred forty-one thousand, five hundred thirty-nine".