1991206996 has 12 divisors (see below), whose sum is σ = 3492931680. Its totient is φ = 993226520.

The previous prime is 1991206993. The next prime is 1991207003. The reversal of 1991206996 is 6996021991.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1991206993) 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 3 ways as a sum of consecutive naturals, for example, 592360 + ... + 595711.

It is an arithmetic number, because the mean of its divisors is an integer number (291077640).

Almost surely, 2^1991206996 is an apocalyptic number.

It is an amenable number.

1991206996 is a deficient number, since it is larger than the sum of its proper divisors (1501724684).

1991206996 is a wasteful number, since it uses less digits than its factorization.

1991206996 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1188494 (or 1188492 counting only the distinct ones).

The product of its (nonzero) digits is 472392, while the sum is 52.

The square root of 1991206996 is about 44622.9424847802. The cubic root of 1991206996 is about 1258.0719222050.

It can be divided in two parts, 199120 and 6996, that added together give a square (206116 = 454²).

The spelling of 1991206996 in words is "one billion, nine hundred ninety-one million, two hundred six thousand, nine hundred ninety-six".