1221996986 has 12 divisors (see below), whose sum is σ = 2132260218. Its totient is φ = 523712952.

The previous prime is 1221996977. The next prime is 1221997001. The reversal of 1221996986 is 6896991221.

It can be written as a sum of positive squares in only one way, i.e., 871371361 + 350625625 = 29519^2 + 18725^2 .

It is a Smith number, since the sum of its digits (53) coincides with the sum of the digits of its prime factors.

It is a Curzon number.

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, 6234581 + ... + 6234776.

Almost surely, 2^1221996986 is an apocalyptic number.

1221996986 is a deficient number, since it is larger than the sum of its proper divisors (910263232).

1221996986 is a wasteful number, since it uses less digits than its factorization.

1221996986 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12469373 (or 12469366 counting only the distinct ones).

The product of its digits is 839808, while the sum is 53.

The square root of 1221996986 is about 34957.0734759076. The cubic root of 1221996986 is about 1069.1124284260.

The spelling of 1221996986 in words is "one billion, two hundred twenty-one million, nine hundred ninety-six thousand, nine hundred eighty-six".