1661928768 has 84 divisors (see below), whose sum is σ = 4879873908. Its totient is φ = 540456960.

The previous prime is 1661928761. The next prime is 1661928797. The reversal of 1661928768 is 8678291661.

1661928768 is a `hidden beast` number, since 16 + 619 + 2 + 8 + 7 + 6 + 8 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 32353344 + 1629575424 = 5688^2 + 40368^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1661928761) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 11571 + ... + 58802.

It is an arithmetic number, because the mean of its divisors is an integer number (58093737).

Almost surely, 2^1661928768 is an apocalyptic number.

1661928768 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is an amenable number.

1661928768 is an abundant number, since it is smaller than the sum of its proper divisors (3217945140).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1661928768 is a wasteful number, since it uses less digits than its factorization.

1661928768 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 70432 (or 70419 counting only the distinct ones).

The product of its digits is 1741824, while the sum is 54.

The square root of 1661928768 is about 40766.7605777060. The cubic root of 1661928768 is about 1184.5065552223.

The spelling of 1661928768 in words is "one billion, six hundred sixty-one million, nine hundred twenty-eight thousand, seven hundred sixty-eight".