1206991986 has 16 divisors (see below), whose sum is σ = 2541036000. Its totient is φ = 381155328.

The previous prime is 1206991963. The next prime is 1206991987. The reversal of 1206991986 is 6891996021.

It is not an unprimeable number, because it can be changed into a prime (1206991987) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5293711 + ... + 5293938.

It is an arithmetic number, because the mean of its divisors is an integer number (158814750).

Almost surely, 2^1206991986 is an apocalyptic number.

1206991986 is an abundant number, since it is smaller than the sum of its proper divisors (1334044014).

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

1206991986 is a wasteful number, since it uses less digits than its factorization.

1206991986 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10587673.

The product of its (nonzero) digits is 419904, while the sum is 51.

The square root of 1206991986 is about 34741.7901956707. The cubic root of 1206991986 is about 1064.7184884900.

The spelling of 1206991986 in words is "one billion, two hundred six million, nine hundred ninety-one thousand, nine hundred eighty-six".