1928648809 has 4 divisors (see below), whose sum is σ = 1930028800. Its totient is φ = 1927268820.

The previous prime is 1928648783. The next prime is 1928648881. The reversal of 1928648809 is 9088468291.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 9088468291 = 7 ⋅1298352613.

It is a cyclic number.

It is not a de Polignac number, because 1928648809 - 2⁹ = 1928648297 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1928648809.

It is not an unprimeable number, because it can be changed into a prime (1928643809) 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 in 3 ways as a sum of consecutive naturals, for example, 687897 + ... + 690694.

It is an arithmetic number, because the mean of its divisors is an integer number (482507200).

Almost surely, 2^1928648809 is an apocalyptic number.

It is an amenable number.

1928648809 is a deficient number, since it is larger than the sum of its proper divisors (1379991).

1928648809 is a wasteful number, since it uses less digits than its factorization.

1928648809 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1379990.

The product of its (nonzero) digits is 1990656, while the sum is 55.

The square root of 1928648809 is about 43916.3842887822. The cubic root of 1928648809 is about 1244.7564474686.

The spelling of 1928648809 in words is "one billion, nine hundred twenty-eight million, six hundred forty-eight thousand, eight hundred nine".