669661836457 has 6 divisors (see below), whose sum is σ = 675861899118. Its totient is φ = 663518138112.

The previous prime is 669661836439. The next prime is 669661836469. The reversal of 669661836457 is 754638166966.

It can be written as a sum of positive squares in 3 ways, for example, as 100608861721 + 569052974736 = 317189^2 + 754356^2 .

It is not a de Polignac number, because 669661836457 - 2¹¹ = 669661834409 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 669661836392 and 669661836401.

It is not an unprimeable number, because it can be changed into a prime (669161836457) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 28170168 + ... + 28193929.

It is an arithmetic number, because the mean of its divisors is an integer number (112643649853).

Almost surely, 2^669661836457 is an apocalyptic number.

It is an amenable number.

669661836457 is a deficient number, since it is larger than the sum of its proper divisors (6200062661).

669661836457 is an equidigital number, since it uses as much as digits as its factorization.

669661836457 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 56364315 (or 56364206 counting only the distinct ones).

The product of its digits is 235146240, while the sum is 67.

The spelling of 669661836457 in words is "six hundred sixty-nine billion, six hundred sixty-one million, eight hundred thirty-six thousand, four hundred fifty-seven".