28478776787 has 16 divisors (see below), whose sum is σ = 29398737024. Its totient is φ = 27572400000.

The previous prime is 28478776763. The next prime is 28478776817. The reversal of 28478776787 is 78767787482.

It is a cyclic number.

It is not a de Polignac number, because 28478776787 - 2¹⁰ = 28478775763 is a prime.

It is a super-2 number, since 2×28478776787² (a number of 22 digits) contains 22 as substring.

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 28478776787.

It is not an unprimeable number, because it can be changed into a prime (28478776757) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 7693037 + ... + 7696737.

It is an arithmetic number, because the mean of its divisors is an integer number (1837421064).

Almost surely, 2^28478776787 is an apocalyptic number.

28478776787 is a deficient number, since it is larger than the sum of its proper divisors (919960237).

28478776787 is a wasteful number, since it uses less digits than its factorization.

28478776787 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5470.

The product of its digits is 413048832, while the sum is 71.

The spelling of 28478776787 in words is "twenty-eight billion, four hundred seventy-eight million, seven hundred seventy-six thousand, seven hundred eighty-seven".