642947 has 2 divisors, whose sum is σ = 642948. Its totient is φ = 642946.

The previous prime is 642937. The next prime is 642953. The reversal of 642947 is 749246.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 642947 - 2⁴ = 642931 is a prime.

It is a Chen prime.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 642947.

It is not a weakly prime, because it can be changed into another prime (642907) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 321473 + 321474.

It is an arithmetic number, because the mean of its divisors is an integer number (321474).

2⁶⁴²⁹⁴⁷ is an apocalyptic number.

642947 is a deficient number, since it is larger than the sum of its proper divisors (1).

642947 is an equidigital number, since it uses as much as digits as its factorization.

642947 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 12096, while the sum is 32.

The square root of 642947 is about 801.8397595530. The cubic root of 642947 is about 86.3094584065.

The spelling of 642947 in words is "six hundred forty-two thousand, nine hundred forty-seven".