642665087 has 2 divisors, whose sum is σ = 642665088. Its totient is φ = 642665086.

The previous prime is 642665083. The next prime is 642665141. The reversal of 642665087 is 780566246.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 642665087 - 2² = 642665083 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (642665083) 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, 321332543 + 321332544.

It is an arithmetic number, because the mean of its divisors is an integer number (321332544).

Almost surely, 2^642665087 is an apocalyptic number.

642665087 is a deficient number, since it is larger than the sum of its proper divisors (1).

642665087 is an equidigital number, since it uses as much as digits as its factorization.

642665087 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 483840, while the sum is 44.

The square root of 642665087 is about 25350.8399663601. The cubic root of 642665087 is about 862.9684185825.

The spelling of 642665087 in words is "six hundred forty-two million, six hundred sixty-five thousand, eighty-seven".