665025461 has 2 divisors, whose sum is σ = 665025462. Its totient is φ = 665025460.

The previous prime is 665025421. The next prime is 665025463. The reversal of 665025461 is 164520566.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 604668100 + 60357361 = 24590^2 + 7769^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-665025461 is a prime.

Together with 665025463, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (665025463) 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, 332512730 + 332512731.

It is an arithmetic number, because the mean of its divisors is an integer number (332512731).

Almost surely, 2^665025461 is an apocalyptic number.

It is an amenable number.

665025461 is a deficient number, since it is larger than the sum of its proper divisors (1).

665025461 is an equidigital number, since it uses as much as digits as its factorization.

665025461 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 43200, while the sum is 35.

The square root of 665025461 is about 25788.0875793456. The cubic root of 665025461 is about 872.8630130664.

The spelling of 665025461 in words is "six hundred sixty-five million, twenty-five thousand, four hundred sixty-one".