28420378664 has 16 divisors (see below), whose sum is σ = 53564317620. Its totient is φ = 14136560640.

The previous prime is 28420378663. The next prime is 28420378687. The reversal of 28420378664 is 46687302482.

It can be written as a sum of positive squares in 2 ways, for example, as 28409102500 + 11276164 = 168550^2 + 3358^2 .

It is not an unprimeable number, because it can be changed into a prime (28420378661) 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, 9201947 + ... + 9205034.

Almost surely, 2^28420378664 is an apocalyptic number.

It is an amenable number.

28420378664 is a deficient number, since it is larger than the sum of its proper divisors (25143938956).

28420378664 is a wasteful number, since it uses less digits than its factorization.

28420378664 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18407180 (or 18407176 counting only the distinct ones).

The product of its (nonzero) digits is 3096576, while the sum is 50.

The spelling of 28420378664 in words is "twenty-eight billion, four hundred twenty million, three hundred seventy-eight thousand, six hundred sixty-four".