1662728909 has 2 divisors, whose sum is σ = 1662728910. Its totient is φ = 1662728908.

The previous prime is 1662728867. The next prime is 1662728939. The reversal of 1662728909 is 9098272661.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1137173284 + 525555625 = 33722^2 + 22925^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1662728909 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1662728939) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 831364454 + 831364455.

It is an arithmetic number, because the mean of its divisors is an integer number (831364455).

Almost surely, 2^1662728909 is an apocalyptic number.

It is an amenable number.

1662728909 is a deficient number, since it is larger than the sum of its proper divisors (1).

1662728909 is an equidigital number, since it uses as much as digits as its factorization.

1662728909 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 653184, while the sum is 50.

The square root of 1662728909 is about 40776.5730413923. The cubic root of 1662728909 is about 1184.6966195652.

The spelling of 1662728909 in words is "one billion, six hundred sixty-two million, seven hundred twenty-eight thousand, nine hundred nine".