2208728019978 has 12 divisors (see below), whose sum is σ = 4785577376658. Its totient is φ = 736242673320.

The previous prime is 2208728019923. The next prime is 2208728019997. The reversal of 2208728019978 is 8799108278022.

2208728019978 is a `hidden beast` number, since 2 + 20 + 87 + 280 + 199 + 78 = 666.

It can be written as a sum of positive squares in only one way, i.e., 2124985499289 + 83742520689 = 1457733^2 + 289383^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 61353556093 + ... + 61353556128.

Almost surely, 2^{2208728019978} is an apocalyptic number.

2208728019978 is an abundant number, since it is smaller than the sum of its proper divisors (2576849356680).

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

2208728019978 is a wasteful number, since it uses less digits than its factorization.

2208728019978 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 122707112229 (or 122707112226 counting only the distinct ones).

The product of its (nonzero) digits is 16257024, while the sum is 63.

Adding to 2208728019978 its sum of digits (63), we get a square (2208728020041 = 1486179²).

The spelling of 2208728019978 in words is "two trillion, two hundred eight billion, seven hundred twenty-eight million, nineteen thousand, nine hundred seventy-eight".