545668691 has 2 divisors, whose sum is σ = 545668692. Its totient is φ = 545668690.

The previous prime is 545668687. The next prime is 545668709. The reversal of 545668691 is 196866545.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 545668691 - 2² = 545668687 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (545668621) 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, 272834345 + 272834346.

It is an arithmetic number, because the mean of its divisors is an integer number (272834346).

Almost surely, 2^545668691 is an apocalyptic number.

545668691 is a deficient number, since it is larger than the sum of its proper divisors (1).

545668691 is an equidigital number, since it uses as much as digits as its factorization.

545668691 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1555200, while the sum is 50.

The square root of 545668691 is about 23359.5524571855. The cubic root of 545668691 is about 817.1648523478.

It can be divided in two parts, 5456 and 68691, that added together give a palindrome (74147).

The spelling of 545668691 in words is "five hundred forty-five million, six hundred sixty-eight thousand, six hundred ninety-one".