642804671 has 2 divisors, whose sum is σ = 642804672. Its totient is φ = 642804670.

The previous prime is 642804611. The next prime is 642804689. The reversal of 642804671 is 176408246.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 642804671 - 2⁶ = 642804607 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (642804611) 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, 321402335 + 321402336.

It is an arithmetic number, because the mean of its divisors is an integer number (321402336).

Almost surely, 2^642804671 is an apocalyptic number.

642804671 is a deficient number, since it is larger than the sum of its proper divisors (1).

642804671 is an equidigital number, since it uses as much as digits as its factorization.

642804671 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 64512, while the sum is 38.

The square root of 642804671 is about 25353.5928617622. The cubic root of 642804671 is about 863.0308916945.

The spelling of 642804671 in words is "six hundred forty-two million, eight hundred four thousand, six hundred seventy-one".