28000002978 has 24 divisors (see below), whose sum is σ = 60676804188. Its totient is φ = 9331775712.

The previous prime is 28000002929. The next prime is 28000003007. The reversal of 28000002978 is 87920000082.

It can be written as a sum of positive squares in 2 ways, for example, as 25444397169 + 2555605809 = 159513^2 + 50553^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 16425 + ... + 237212.

Almost surely, 2^28000002978 is an apocalyptic number.

28000002978 is an abundant number, since it is smaller than the sum of its proper divisors (32676801210).

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

28000002978 is a wasteful number, since it uses less digits than its factorization.

28000002978 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 259778 (or 259775 counting only the distinct ones).

The product of its (nonzero) digits is 16128, while the sum is 36.

The spelling of 28000002978 in words is "twenty-eight billion, two thousand, nine hundred seventy-eight".