1662728409 has 6 divisors (see below), whose sum is σ = 2401718826. Its totient is φ = 1108485600.

The previous prime is 1662728393. The next prime is 1662728453. The reversal of 1662728409 is 9048272661.

It is a happy number.

1662728409 is a `hidden beast` number, since 16 + 627 + 2 + 8 + 4 + 0 + 9 = 666.

1662728409 is digitally balanced in base 4, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in only one way, i.e., 1645113600 + 17614809 = 40560^2 + 4197^2 .

It is not a de Polignac number, because 1662728409 - 2⁴ = 1662728393 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1662728909) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 92373792 + ... + 92373809.

It is an arithmetic number, because the mean of its divisors is an integer number (400286471).

Almost surely, 2^1662728409 is an apocalyptic number.

It is an amenable number.

1662728409 is a deficient number, since it is larger than the sum of its proper divisors (738990417).

1662728409 is a wasteful number, since it uses less digits than its factorization.

1662728409 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 184747607 (or 184747604 counting only the distinct ones).

The product of its (nonzero) digits is 290304, while the sum is 45.

The square root of 1662728409 is about 40776.5669104205. The cubic root of 1662728409 is about 1184.6965008150.

The spelling of 1662728409 in words is "one billion, six hundred sixty-two million, seven hundred twenty-eight thousand, four hundred nine".