1284543661 has 4 divisors (see below), whose sum is σ = 1328838300. Its totient is φ = 1240249024.

The previous prime is 1284543649. The next prime is 1284543671. The reversal of 1284543661 is 1663454821.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 608855625 + 675688036 = 24675^2 + 25994^2 .

It is a cyclic number.

It is not a de Polignac number, because 1284543661 - 2¹¹ = 1284541613 is a prime.

It is a Duffinian number.

It is a zygodrome in base 8.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1284543641) 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 in 3 ways as a sum of consecutive naturals, for example, 22147276 + ... + 22147333.

It is an arithmetic number, because the mean of its divisors is an integer number (332209575).

Almost surely, 2^1284543661 is an apocalyptic number.

It is an amenable number.

1284543661 is a deficient number, since it is larger than the sum of its proper divisors (44294639).

1284543661 is an equidigital number, since it uses as much as digits as its factorization.

1284543661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 44294638.

The product of its digits is 138240, while the sum is 40.

The square root of 1284543661 is about 35840.5309809997. The cubic root of 1284543661 is about 1087.0502579658.

The spelling of 1284543661 in words is "one billion, two hundred eighty-four million, five hundred forty-three thousand, six hundred sixty-one".