1985816788 has 12 divisors (see below), whose sum is σ = 3569103412. Its totient is φ = 966072960.

The previous prime is 1985816779. The next prime is 1985816813. The reversal of 1985816788 is 8876185891.

It can be written as a sum of positive squares in 2 ways, for example, as 1782697284 + 203119504 = 42222^2 + 14252^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6708693 + ... + 6708988.

Almost surely, 2^1985816788 is an apocalyptic number.

It is an amenable number.

1985816788 is a deficient number, since it is larger than the sum of its proper divisors (1583286624).

1985816788 is a wasteful number, since it uses less digits than its factorization.

1985816788 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13417722 (or 13417720 counting only the distinct ones).

The product of its digits is 7741440, while the sum is 61.

The square root of 1985816788 is about 44562.5042833098. The cubic root of 1985816788 is about 1256.9356938521.

The spelling of 1985816788 in words is "one billion, nine hundred eighty-five million, eight hundred sixteen thousand, seven hundred eighty-eight".