665726543 has 2 divisors, whose sum is σ = 665726544. Its totient is φ = 665726542.

The previous prime is 665726527. The next prime is 665726569. The reversal of 665726543 is 345627566.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 665726543 - 2⁴ = 665726527 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 665726494 and 665726503.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (665728543) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 332863271 + 332863272.

It is an arithmetic number, because the mean of its divisors is an integer number (332863272).

Almost surely, 2^665726543 is an apocalyptic number.

665726543 is a deficient number, since it is larger than the sum of its proper divisors (1).

665726543 is an equidigital number, since it uses as much as digits as its factorization.

665726543 is an evil number, because the sum of its binary digits is even.

The product of its digits is 907200, while the sum is 44.

The square root of 665726543 is about 25801.6771354112. The cubic root of 665726543 is about 873.1696347254.

The spelling of 665726543 in words is "six hundred sixty-five million, seven hundred twenty-six thousand, five hundred forty-three".