1642691407909 has 2 divisors, whose sum is σ = 1642691407910. Its totient is φ = 1642691407908.

The previous prime is 1642691407867. The next prime is 1642691408011. The reversal of 1642691407909 is 9097041962461.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1446840905409 + 195850502500 = 1202847^2 + 442550^2 .

It is a cyclic number.

It is not a de Polignac number, because 1642691407909 - 2²⁵ = 1642657853477 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1642691407009) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 821345703954 + 821345703955.

It is an arithmetic number, because the mean of its divisors is an integer number (821345703955).

Almost surely, 2^{1642691407909} is an apocalyptic number.

It is an amenable number.

1642691407909 is a deficient number, since it is larger than the sum of its proper divisors (1).

1642691407909 is an equidigital number, since it uses as much as digits as its factorization.

1642691407909 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 5878656, while the sum is 58.

The spelling of 1642691407909 in words is "one trillion, six hundred forty-two billion, six hundred ninety-one million, four hundred seven thousand, nine hundred nine".