1978618285 has 12 divisors (see below), whose sum is σ = 2761989948. Its totient is φ = 1356766656.

The previous prime is 1978618283. The next prime is 1978618331. The reversal of 1978618285 is 5828168791.

It can be written as a sum of positive squares in 2 ways, for example, as 1113023044 + 865595241 = 33362^2 + 29421^2 .

It is not a de Polignac number, because 1978618285 - 2¹ = 1978618283 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1978618283) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 4037752 + ... + 4038241.

It is an arithmetic number, because the mean of its divisors is an integer number (230165829).

Almost surely, 2^1978618285 is an apocalyptic number.

It is an amenable number.

1978618285 is a deficient number, since it is larger than the sum of its proper divisors (783371663).

1978618285 is an equidigital number, since it uses as much as digits as its factorization.

1978618285 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8076012 (or 8076005 counting only the distinct ones).

The product of its digits is 1935360, while the sum is 55.

The square root of 1978618285 is about 44481.6623452856. The cubic root of 1978618285 is about 1255.4150751610.

The spelling of 1978618285 in words is "one billion, nine hundred seventy-eight million, six hundred eighteen thousand, two hundred eighty-five".