28078075805 has 16 divisors (see below), whose sum is σ = 36314670000. Its totient is φ = 20717918208.

The previous prime is 28078075793. The next prime is 28078075813. The reversal of 28078075805 is 50857087082.

It can be written as a sum of positive squares in 8 ways, for example, as 5324766841 + 22753308964 = 72971^2 + 150842^2 .

It is not a de Polignac number, because 28078075805 - 2³² = 23783108509 is a prime.

It is a super-2 number, since 2×28078075805² (a number of 22 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 91742 + ... + 254111.

It is an arithmetic number, because the mean of its divisors is an integer number (2269666875).

Almost surely, 2^28078075805 is an apocalyptic number.

It is an amenable number.

28078075805 is a deficient number, since it is larger than the sum of its proper divisors (8236594195).

28078075805 is a wasteful number, since it uses less digits than its factorization.

28078075805 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 347120.

The product of its (nonzero) digits is 1254400, while the sum is 50.

The spelling of 28078075805 in words is "twenty-eight billion, seventy-eight million, seventy-five thousand, eight hundred five".